Still Struggling...


A

Aria

Hi,
I'm still struggling to organize my tables and fields but I'm not as
*totally confused* as my original post; at least I hope I'm not. I'm new to
Access. This is my first database and I fluctuate between feeling hopeful I
can do this one minute and despairing that I can't the next because I've
thought of yet another complication that I don't know how to handle. I have
scoured the Internet and this disscussion group searching for the answers
that I need. I found some but I am still at a loss as to what to do about
others. I was wondering if someone would be kind enough to review my table
structure and respond to some questions at the end. I am truly grateful.

The information is as follows:

tblEmployees
Inactive- Yes/No
Date- Date/Time
Date Modified- Date/Time
Employee ID- (PK) Auto number Long Integer
School Data (Classification, Title, Dept. Name, Subject)- text
Personal Info (LN FN MI etc.)- text
Emergency Info - text

tblKeys
Key ID (PK)- text
Campus- text
Wing- text
RoomType(Classroom, Auditorium, Grand Master, etc.)- text

tblKeysEmployees
Key ID- composite key(FK to tblKeys)- text
EmployeeID-composite key (FK to tblEmployees)- Autonumber

tblKeysRequests
Request ID-Autonumber
Key ID (FK to tblKeys)- text
Emp. ID
Rm. number- text--I think there is a problem here. This info is part of
tblrooms.
Rm. phone- text
Date Requested- Date/time
Date Recvd.- Date/time
Date Issued- Date/time

tblRooms
Key ID (PK)-text
Room number- text
Remarks-text

tblSubs
Sub ID (PK)-Autonumber
SubLN-text
SubFN-text
MI-text
SubPhone-text
Key ID (FK to tblKeys)
Date Issued-Date/Time
Date Returned-Date/Time

If you're still reading, I have the following questions:
1. How many fields are too many in a table? I understand that Access will
accept up to 255. I read a post that suggested that 20-30 fields may indicate
there may be a normalization problem. I'm wondering about tblEmployees where
there are approx. 25 fields.

2.tblRooms has a field for Rm.#; the problem is that not all rooms have a #.
Ex.-Storage rms., clinic, auditorium, etc. This is why I added remarks to
tblRooms because I may have to describe a location rather than a room #. Will
there be a problem with this method?
One of the desired reports is a reverse directory by room #/room phone #.
The phone # is currently in tblEmployees. Should it be moved to tblRooms? If
I leave it where it is, will I be able to update any queries and reports?
I've read that multitable queries aren't updateable. We have had mass staff
room changes right before the school year begins. It just seems it would be
better if the phone # was listed with tblRooms but someone told me that's
incorrect.

3. I forgot to include the following fields: Date assigned, Return Date and
Permission to Retain (over the summer) for Emp. Keys. Should this be added to
tblKeys or tblEmployees? I was told not to put *anything* into the junction
table (tblKeysEmployees) besides the composite key already listed.

4.Keys Requests--Somethimes are request will not have a name associated with
it. For instance, we need to request a key for the vault. I have not
accounted for this situation and don't know how to handle it. If I need to
order a sub. key, I can use the name of the permanent staff member associated
with that room. What do I do about the vault? Should I enter "vault" in the
emp. table w/o any additional data?

5. Maybe I should cross this bridge when I get to it but I eventually will
get to the point where I will make forms and subforms. There are approx. 400
seperate keys, not including multiple copies of the same key. If I have a
combo box, is there a way to filter so that I am not looking at all 400
possiblities at once?

I am so sorry if this is too long and I'm asking too many questions at once.
I understand that you are trying to help as many people as possible. I have
searched and searched for answers and tried to adapt the customers/orders
format as much as possible to my situation but...I need help.
 
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B

BruceM

Responses inline.

Aria said:
Hi,
I'm still struggling to organize my tables and fields but I'm not as
*totally confused* as my original post; at least I hope I'm not. I'm new
to
Access. This is my first database and I fluctuate between feeling hopeful
I
can do this one minute and despairing that I can't the next because I've
thought of yet another complication that I don't know how to handle. I
have
scoured the Internet and this disscussion group searching for the answers
that I need. I found some but I am still at a loss as to what to do about
others. I was wondering if someone would be kind enough to review my table
structure and respond to some questions at the end. I am truly grateful.

The information is as follows:

tblEmployees
Inactive- Yes/No
Date- Date/Time
Date Modified- Date/Time
Employee ID- (PK) Auto number Long Integer
School Data (Classification, Title, Dept. Name, Subject)- text
Personal Info (LN FN MI etc.)- text
Emergency Info - text
I ws going to say that SchoolData and PersonalInfo should be broken into
several fields each, but later you said something about the number of fields
in the table, so it seems the way you have written it here is a sort of
shorthand, and that you have separate fields as needed.
tblKeys
Key ID (PK)- text
Campus- text
Wing- text
RoomType(Classroom, Auditorium, Grand Master, etc.)- text
One lock could have several keys (one for each of several people). This
suggests you need a Locks table, separate from the Keys table. Each lock
could have several keys, so there is a one-to-many relationship between
locks and keys. Since a filing cabinet could be moved from one room to
another, the correlation between locks and rooms may need to be flexible.
One approach to the Locks table would be to have fields for Campus, Wing,
and Room. You could query the table for locks that go with a particular
campus, building, wing, and room, or for all of the locks for a campus, or
all of the locks for a building, etc.
You may want to build some lookup tables (very different from lookup fields)
to use for selecting campus, wing, and roomtype from combo boxes on your
form. For instance, a RoomType table may be simply a listing of RoomTypes.
Make a query based on this table (sorted by RoomType), and use the query as
the Row Source for a RoomType combo box on your Keys form.
tblKeysEmployees
Key ID- composite key(FK to tblKeys)- text
EmployeeID-composite key (FK to tblEmployees)- Autonumber
EmployeeID must be Number (Long Integer), not Autonumber. It is a foreign
key field, so it cannot be assigned automatically. Rather, it gets its
value from the parent table when a record is created. The two fields
together can be a composite PK for this table, but are not by themselves
composite keys.
tblKeysRequests
Request ID-Autonumber
Key ID (FK to tblKeys)- text
Emp. ID
Rm. number- text--I think there is a problem here. This info is part of
tblrooms.
Rm. phone- text
Date Requested- Date/time
Date Recvd.- Date/time
Date Issued- Date/time


tblRooms
Key ID (PK)-text
Room number- text
Remarks-text
KeyID as the PK of tblRooms could be confusing.
tblSubs
Sub ID (PK)-Autonumber
SubLN-text
SubFN-text
MI-text
SubPhone-text
Key ID (FK to tblKeys)
Date Issued-Date/Time
Date Returned-Date/Time
This table's purpose is unclear.
If you're still reading, I have the following questions:
1. How many fields are too many in a table? I understand that Access will
accept up to 255. I read a post that suggested that 20-30 fields may
indicate
there may be a normalization problem. I'm wondering about tblEmployees
where
there are approx. 25 fields.
No problem. More than 30 fields could suggest normalization problems, but
it not an invariable rule. If the SchoolData fields are not all filled in
for every record it could be that SchoolData could be in a separate table.
Nothing else stands out much.
2.tblRooms has a field for Rm.#; the problem is that not all rooms have a
#.
Ex.-Storage rms., clinic, auditorium, etc. This is why I added remarks to
tblRooms because I may have to describe a location rather than a room #.
Will
there be a problem with this method?
Only if RoomNumber is a linking field. By the way, I assume you are using
the number sign for description, not as a field name. Names should include
only letters, number, and underscores. Spaces and other non-alphanumeric
characters are best avoided.
One of the desired reports is a reverse directory by room #/room phone #.
The phone # is currently in tblEmployees. Should it be moved to tblRooms?
If
I leave it where it is, will I be able to update any queries and reports?
I've read that multitable queries aren't updateable. We have had mass
staff
room changes right before the school year begins. It just seems it would
be
better if the phone # was listed with tblRooms but someone told me that's
incorrect.
If the phone number is associated with a room it should be part of a room
record. Presumably an employee can be associated with several rooms, and
vice versa. However, if an employee has an office where only he or she
answers the phone, the phone number is associated with the employee. Often
in such case the phone number follows the employee if they move to another
office. There is no single answer to your question. Your database can be
made to accept either a phone associated with a room or with an employee, or
both. It does start to become more complex if you have both situations.
3. I forgot to include the following fields: Date assigned, Return Date
and
Permission to Retain (over the summer) for Emp. Keys. Should this be added
to
tblKeys or tblEmployees? I was told not to put *anything* into the
junction
table (tblKeysEmployees) besides the composite key already listed.
You can have other fields in a junction table. For instance, the
KeysEmployees junction table may include a DateIssued field, which is a
property of neither the Employee nor the Key, but rather of this particular
key together with this particular employee. If a key may be retained over
the summer by one employee, but not another, then this too is a candidate
for a field in the junction table.
4.Keys Requests--Somethimes are request will not have a name associated
with
it. For instance, we need to request a key for the vault. I have not
accounted for this situation and don't know how to handle it. If I need to
order a sub. key, I can use the name of the permanent staff member
associated
with that room. What do I do about the vault? Should I enter "vault" in
the
emp. table w/o any additional data?
Vault chould not be in the employee table, but the situation is unclear. Is
nobody responsible for the vault key? How will you know who has it? How do
you know now?
5. Maybe I should cross this bridge when I get to it but I eventually will
get to the point where I will make forms and subforms. There are approx.
400
seperate keys, not including multiple copies of the same key. If I have a
combo box, is there a way to filter so that I am not looking at all 400
possiblities at once?
Again, I'm not sure what you're asking. You will need forms and subforms as
soon as you start doing data entry. It may be best to begin with just
tblKeys, tblEmployees, and tblKeysEmployees, just as a test to see how to
work with the junction table arrangement.
 
A

Aria

Bruce,
First, I would really like to thank you for responding. I need to clarify
some of the information that seems to be confusing. tblSubs is a table for
temporary, roving district staff. They may be employed at any district site
anywhere from a couple of hours to long-term(months). They need access to
their assignment location and if they are certificated, temporary passwords
for certain reports.

My comments are as follows:
tblEmployees
Inactive- Yes/No
Date- Date/Time
Date Modified- Date/Time
Employee ID- (PK) Auto number Long Integer
School Data (Classification, Title, Dept. Name, Subject)- text
Personal Info (LN FN MI etc.)- text
Emergency Info - text
I ws going to say that SchoolData and PersonalInfo should be broken into
several fields each, but later you said something about the number of fields
in the table, so it seems the way you have written it here is a sort of
shorthand, and that you have separate fields as needed.

I think I'm fairly comfortable with this table. I just thought maybe it
needed to be broken down (not that I'm looking for another table to put in).
Yes, the fields are seperate.
tblKeys
Key ID (PK)- text
Campus- text
Wing- text
RoomType(Classroom, Auditorium, Grand Master, etc.)- text
One lock could have several keys (one for each of several people). This
suggests you need a Locks table, separate from the Keys table. Each lock
could have several keys, so there is a one-to-many relationship between
locks and keys. Since a filing cabinet could be moved from one room to
another, the correlation between locks and rooms may need to be flexible.
One approach to the Locks table would be to have fields for Campus, Wing,
and Room. You could query the table for locks that go with a particular
campus, building, wing, and room, or for all of the locks for a campus, or
all of the locks for a building, etc.
You may want to build some lookup tables (very different from lookup fields)
to use for selecting campus, wing, and roomtype from combo boxes on your
form. For instance, a RoomType table may be simply a listing of RoomTypes.
Make a query based on this table (sorted by RoomType), and use the query as
the Row Source for a RoomType combo box on your Keys form.


Now, this is where you lose me. I don't understand the purpose of a Locks
table. Isn't that what the keys table is for? We are only interested in the
locks as far as what key will staff to gain access to the room, gate,
stadium, etc. We don't normally track file cabinet keys. We may if the
contents are extremely confidential.
tblKeysEmployees
Key ID- composite key(FK to tblKeys)- text
EmployeeID-composite key (FK to tblEmployees)- Autonumber
EmployeeID must be Number (Long Integer), not Autonumber. It is a foreign
key field, so it cannot be assigned automatically. Rather, it gets its
value from the parent table when a record is created. The two fields
together can be a composite PK for this table, but are not by themselves
composite keys.

Sorry; I dropped the ball on this one. This *is* long interger. I forgot to
make the change in designation from my original.>
tblRooms
Key ID (PK)-text
Room number- text
Remarks-text
KeyID as the PK of tblRooms could be confusing.

Again, you lost me on this one. Why is the KeyID confusing? It relates to
the room; knowing the key ID will allow you access. My thinking was that if I
could do a parameter query (is that what I would want?) by room, I would know
which key will unlock it. Then I could make a key request or whatever else
needs to be done.
tblSubs
Sub ID (PK)-Autonumber
SubLN-text
SubFN-text
MI-text
SubPhone-text
Key ID (FK to tblKeys)
Date Issued-Date/Time
Date Returned-Date/Time
This table's purpose is unclear.

I'm sorry. I should have explained in the beginning. Like I stated, this is
for temporary, roving staff. We need Access only in relation to keys for this
group. We have other applications for the rest of the information we need.
1. How many fields are too many in a table? I understand that Access will
accept up to 255. I read a post that suggested that 20-30 fields may
indicate
there may be a normalization problem. I'm wondering about tblEmployees
where
there are approx. 25 fields.
No problem. More than 30 fields could suggest normalization problems, but
it not an invariable rule. If the SchoolData fields are not all filled in
for every record it could be that SchoolData could be in a separate table.
Nothing else stands out much.

All the fields relating to school data wil be filled in, so I guess we're
good here.
2.tblRooms has a field for Rm.#; the problem is that not all rooms have a
#.
Ex.-Storage rms., clinic, auditorium, etc. This is why I added remarks to
tblRooms because I may have to describe a location rather than a room #.
Will
there be a problem with this method?
Only if RoomNumber is a linking field. By the way, I assume you are using
the number sign for description, not as a field name. Names should include
only letters, number, and underscores. Spaces and other non-alphanumeric
characters are best avoided.

Oh my gosh! How many times have I read the same thing and because I *knew*
my fields weren't like that, moved on. Well, I just wanted to double check
and lo and behold, there it was; a # sign in my field name. Thanks for the
heads up!
One of the desired reports is a reverse directory by room #/room phone #.
The phone # is currently in tblEmployees. Should it be moved to tblRooms?
If
I leave it where it is, will I be able to update any queries and reports?
I've read that multitable queries aren't updateable. We have had mass
staff
room changes right before the school year begins. It just seems it would
be
better if the phone # was listed with tblRooms but someone told me that's
incorrect.
If the phone number is associated with a room it should be part of a room
record. Presumably an employee can be associated with several rooms, and
vice versa. However, if an employee has an office where only he or she
answers the phone, the phone number is associated with the employee. Often
in such case the phone number follows the employee if they move to another
office. There is no single answer to your question. Your database can be
made to accept either a phone associated with a room or with an employee, or
both. It does start to become more complex if you have both situations.

Well, for classroom staff, if they have to change rooms (happens every year,
so I have no illusions here), they switch to the new rooms' phone #. For
office staff, it could go either way. What do I need to do if anything?
3. I forgot to include the following fields: Date assigned, Return Date
and
Permission to Retain (over the summer) for Emp. Keys. Should this be added
to
tblKeys or tblEmployees? I was told not to put *anything* into the
junction
table (tblKeysEmployees) besides the composite key already listed.
You can have other fields in a junction table. For instance, the
KeysEmployees junction table may include a DateIssued field, which is a
property of neither the Employee nor the Key, but rather of this particular
key together with this particular employee. If a key may be retained over
the summer by one employee, but not another, then this too is a candidate
for a field in the junction table.

Your statements are true enough; only the master keys are coded to a
particular employee. Classroom keys are a little more generic in that anyone
who works out of that classroom or office will have the same key. O.k., I'll
put the new fields here.
4.Keys Requests--Sometimes a request will not have a name associated
with
it. For instance, we need to request a key for the vault. I have not
accounted for this situation and don't know how to handle it. If I need to
order a sub. key, I can use the name of the permanent staff member
associated
with that room. What do I do about the vault? Should I enter "vault" in
the
emp. table w/o any additional data?
Vault chould not be in the employee table, but the situation is unclear. Is
nobody responsible for the vault key? How will you know who has it? How do
you know now?

Every key available on both campuses should be in the vault. Theoretically,
vault keys remain in the vault. I guess I'm responsible for those keys but
anyone who has the combination can remove a key without my knowledge. I guess
I could list myself and under Remarks indicate it's a vault request.
5. Maybe I should cross this bridge when I get to it but I eventually will
get to the point where I will make forms and subforms. There are approx.
400
seperate keys, not including multiple copies of the same key. If I have a
combo box, is there a way to filter so that I am not looking at all 400
possiblities at once?
Again, I'm not sure what you're asking. You will need forms and subforms as
soon as you start doing data entry. It may be best to begin with just
tblKeys, tblEmployees, and tblKeysEmployees, just as a test to see how to
work with the junction table arrangement.

I'll hold off on this question and concentrate on getting the tables and
fields correct.

Bruce, again, I really appreciate all of your help. Thanks so much for
talking me through it!
 
B

Beetle

Hate to throw in the monkey wrench, but I'm going to have to disagree
with some of what's been posted (comments inline).
tblEmployees
Inactive- Yes/No
Date- Date/Time
Date Modified- Date/Time
Employee ID- (PK) Auto number Long Integer
School Data (Classification, Title, Dept. Name, Subject)- text
Personal Info (LN FN MI etc.)- text
Emergency Info - text
Sorry, but the school data belongs in a separate table/tables. With the above
structure you will repeatedly be entering the same descriptive data over and
over. Additionally, what if an instructor teaches more than one Subject, works
in more than one Dept., etc? You will have to enter additional records for
the same employee.
tblKeys
Key ID (PK)- text
Campus- text
Wing- text
RoomType(Classroom, Auditorium, Grand Master, etc.)- text
Again, this is wrong. Campus, Wing and RoomType are not attributes
of the Key. This table should have RoomID as a foreign key to tblRooms
and probably not much else, unless you store some other descriptive
information about the key itself, like "color" or something. Think of it
this way - you said you don't really track filing cabinet keys so we'll
just take rooms into consideration here. A key opens a room. Period.
The Room Type and the Wing in which that room is located are attributes
of the Room, not the Key. Likewise, the Campus that Wing is located in is
an attribute of the Wing (not the Room or the Key). You should have separate
tables for Campus' and Wings
tblRooms
Key ID (PK)-text
Room number- text
Remarks-text
This table should have RoomID as a PK (KeyID does not belong here).
A room can have many keys, but a key can only open one room,
so RoomID goes in tblKeys as a foreign key, not the other way around.
tblSubs
Sub ID (PK)-Autonumber
SubLN-text
SubFN-text
MI-text
SubPhone-text
Key ID (FK to tblKeys)
Date Issued-Date/Time
Date Returned-Date/Time
IMO this table is unecessary. Whether an employee is "full time" or
"temporary" is just an attribute that would go in tblEmployees. The fact
that a person may come and go as a member of your staff is irrelevant
to the fact that that person was in posession of a certain key at a
certain time. The date that a key was issued/returned belongs in
tblKeysEmployees.

You might be thinking "great, now I have to add more tables" but keep
in mind that in an application like this you will typically have several
tables
that will basically just be "lookup" tables. They aren't really a big
deal to set up. Just from the little I know about your app, I would say
you would probably have the following tables that would be
"lookup" tables;

tblClassifications

tblDepartments

tblSubjects

tblCampuses

tblWings

tblRoomTypes

You may also need some additional junction tables, depending on if - as
I stated earlier - an instructor can teach more than one subject, work in
more than one department, etc.

For you first app, you didn't exactly pick a simple one, but everyone loves
a challenge, right? <g>

Good luck and welcome to the world of Access.
 
B

BruceM

Beetle said:
Hate to throw in the monkey wrench, but I'm going to have to disagree
with some of what's been posted (comments inline).


Sorry, but the school data belongs in a separate table/tables. With the
above
structure you will repeatedly be entering the same descriptive data over
and
over. Additionally, what if an instructor teaches more than one Subject,
works
in more than one Dept., etc? You will have to enter additional records for
the same employee.
You make some valid points about subjects and departments, and about titles
too if somebody holds more than one. I'm not sure exactly what is meant by
classification, so I couldn't say if there could be more than one. It
depends in part on how they do things. However, the posting was about keys,
so correctly or not I chose not to get into a discussion of the Employee
table.
Again, this is wrong. Campus, Wing and RoomType are not attributes
of the Key. This table should have RoomID as a foreign key to tblRooms
and probably not much else, unless you store some other descriptive
information about the key itself, like "color" or something. Think of it
this way - you said you don't really track filing cabinet keys so we'll
just take rooms into consideration here. A key opens a room. Period.
The Room Type and the Wing in which that room is located are attributes
of the Room, not the Key. Likewise, the Campus that Wing is located in is
an attribute of the Wing (not the Room or the Key). You should have
separate
tables for Campus' and Wings
You may be correct about the RoomID as the FK. However, it isn't
necessarily as simple as a key opening a room (period). The building could
have a key, for instance, or there could be a padlock or other lock that is
not a room (or supply closet) lock. The OP said they don't "really" track
file cabinet keys and such, but if they ever have a key to something other
than a room provisions will need to be made for that. This is why I
suggeested a Locks table. A lock could have several keys. A Locks table
would need to specify the lock's location in a way that does not necessarily
reference a room (in what room is a building's front door located?). Also,
a room having several different locks (in an auditorium, for instance, or a
room with an outside door and a hallway door) is not out of the question.
 
B

BruceM

Aria said:
Bruce,
First, I would really like to thank you for responding. I need to clarify
some of the information that seems to be confusing. tblSubs is a table for
temporary, roving district staff. They may be employed at any district
site
anywhere from a couple of hours to long-term(months). They need access to
their assignment location and if they are certificated, temporary
passwords
for certain reports.

My comments are as follows:
I ws going to say that SchoolData and PersonalInfo should be broken into
several fields each, but later you said something about the number of
fields
in the table, so it seems the way you have written it here is a sort of
shorthand, and that you have separate fields as needed.

I think I'm fairly comfortable with this table. I just thought maybe it
needed to be broken down (not that I'm looking for another table to put
in).
Yes, the fields are seperate.


One lock could have several keys (one for each of several people). This
suggests you need a Locks table, separate from the Keys table. Each lock
could have several keys, so there is a one-to-many relationship between
locks and keys. Since a filing cabinet could be moved from one room to
another, the correlation between locks and rooms may need to be flexible.
One approach to the Locks table would be to have fields for Campus, Wing,
and Room. You could query the table for locks that go with a particular
campus, building, wing, and room, or for all of the locks for a campus, or
all of the locks for a building, etc.
You may want to build some lookup tables (very different from lookup
fields)
to use for selecting campus, wing, and roomtype from combo boxes on your
form. For instance, a RoomType table may be simply a listing of RoomTypes.
Make a query based on this table (sorted by RoomType), and use the query
as
the Row Source for a RoomType combo box on your Keys form.


Now, this is where you lose me. I don't understand the purpose of a Locks
table. Isn't that what the keys table is for? We are only interested in
the
locks as far as what key will staff to gain access to the room, gate,
stadium, etc. We don't normally track file cabinet keys. We may if the
contents are extremely confidential.
A lock could have several keys. If a supply closet has three keys issued
and a fourth person needs a key, you need to know that another key has to be
made. The keys is an attribute of the lock, not the other way around. At
least that's how I see it. If a lock is changed you need a way to find the
existing keys so they can be swapped with the new ones.
EmployeeID must be Number (Long Integer), not Autonumber. It is a foreign
key field, so it cannot be assigned automatically. Rather, it gets its
value from the parent table when a record is created. The two fields
together can be a composite PK for this table, but are not by themselves
composite keys.

Sorry; I dropped the ball on this one. This *is* long interger. I forgot
to
make the change in designation from my original.>
KeyID as the PK of tblRooms could be confusing.

Again, you lost me on this one. Why is the KeyID confusing? It relates to
the room; knowing the key ID will allow you access. My thinking was that
if I
could do a parameter query (is that what I would want?) by room, I would
know
which key will unlock it. Then I could make a key request or whatever else
needs to be done.
As Beetle pointed out, RoomID is the PK of tblRooms (although again, I would
identify Locks, which are not necessarily for rooms). A room (or lock)
could have several keys, so KeyID is the FK to tblRooms (or tblLocks).
This table's purpose is unclear.

I'm sorry. I should have explained in the beginning. Like I stated, this
is
for temporary, roving staff. We need Access only in relation to keys for
this
group. We have other applications for the rest of the information we need.
Again, as Beetle suggested there is no need for this group to be separate
from the people listed in tblEmployees (or tblPersonnel, if you prefer to
look at it that way).
No problem. More than 30 fields could suggest normalization problems, but
it not an invariable rule. If the SchoolData fields are not all filled in
for every record it could be that SchoolData could be in a separate table.
Nothing else stands out much.

All the fields relating to school data wil be filled in, so I guess we're
good here.
Beetle made a good point about this if there somebody could have more than
one subject, etc. I wish he had included more of the remarks when he
replied. He posted that he was disagreeing with me (I think) about some
things, but he did not include those things, so this thread is a bit
fragmented. I have some other remarks in response to his reply.
Only if RoomNumber is a linking field. By the way, I assume you are using
the number sign for description, not as a field name. Names should include
only letters, number, and underscores. Spaces and other non-alphanumeric
characters are best avoided.

Oh my gosh! How many times have I read the same thing and because I *knew*
my fields weren't like that, moved on. Well, I just wanted to double check
and lo and behold, there it was; a # sign in my field name. Thanks for the
heads up!


If the phone number is associated with a room it should be part of a room
record. Presumably an employee can be associated with several rooms, and
vice versa. However, if an employee has an office where only he or she
answers the phone, the phone number is associated with the employee. Often
in such case the phone number follows the employee if they move to another
office. There is no single answer to your question. Your database can be
made to accept either a phone associated with a room or with an employee,
or
both. It does start to become more complex if you have both situations.

Well, for classroom staff, if they have to change rooms (happens every
year,
so I have no illusions here), they switch to the new rooms' phone #. For
office staff, it could go either way. What do I need to do if anything?
If a staff member has a fixed phone number, that should be part of their
Employee record. If a room has a phone number, that is an attribute of the
room, so you would start to get into having the phone number be associated
with a person's schedule, which is an other project. Essentially you would
need to have the person's schedule. If they are in room 101 from 10:00 -
noon, from those hours you would need to contact them there. I'm not sure
there is a simple answer to this question.
You can have other fields in a junction table. For instance, the
KeysEmployees junction table may include a DateIssued field, which is a
property of neither the Employee nor the Key, but rather of this
particular
key together with this particular employee. If a key may be retained over
the summer by one employee, but not another, then this too is a candidate
for a field in the junction table.

Your statements are true enough; only the master keys are coded to a
particular employee. Classroom keys are a little more generic in that
anyone
who works out of that classroom or office will have the same key. O.k.,
I'll
put the new fields here.


Vault chould not be in the employee table, but the situation is unclear.
Is
nobody responsible for the vault key? How will you know who has it? How do
you know now?

Every key available on both campuses should be in the vault.
Theoretically,
vault keys remain in the vault. I guess I'm responsible for those keys but
anyone who has the combination can remove a key without my knowledge. I
guess
I could list myself and under Remarks indicate it's a vault request.
It sounds as if the vault contains the originals from which copies are made.
If so, and if the vault has a combination lock, I'm not sure the vault fits
into your schema.
 
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A

Aria

Beetle,
(lol) Yes, you have definitely thrown a monkey wrench into the works! You
have raised some valid points that I need to take into account. I have
thought about what you posted and would like to clarify some points and ask
additional questions.
Sorry, but the school data belongs in a separate table/tables. With the above
structure you will repeatedly be entering the same descriptive data over and
over. Additionally, what if an instructor teaches more than one Subject, works
in more than one Dept., etc? You will have to enter additional records for
the same employee.
Does school data need an additional table based solely on instuctors
teaching more than one subject? You are correct though. Teachers can teach
more than one subject. I only ask because you said, "additionally", which
implies that this will need a new table regardless. Other than "Subject", I
don't understand how I would be entering the same information again and
again. What am I missing?
Again, this is wrong. Campus, Wing and RoomType are not attributes
of the Key. This table should have RoomID as a foreign key to tblRooms
and probably not much else, unless you store some other descriptive
information about the key itself, like "color" or something. Think of it
this way - you said you don't really track filing cabinet keys so we'll
just take rooms into consideration here. A key opens a room. Period.
The Room Type and the Wing in which that room is located are attributes
of the Room, not the Key. Likewise, the Campus that Wing is located in is
an attribute of the Wing (not the Room or the Key). You should have separate
tables for Campus' and Wings
Point taken; although I don't understand why the campus location is not a
room attribute. I need to know where that room or storage room is
located(especially since storage rooms don't have room #s). Does it make a
difference if there are only 2 campuses? No? So, is it CampusID (FK to
tblRooms)? Same for tblWings?
Also, I meant to put KeyType (Storage, Classroom, Gate Master, Grand Master,
etc.) as a field here.
This table should have RoomID as a PK (KeyID does not belong here).
A room can have many keys, but a key can only open one room,
so RoomID goes in tblKeys as a foreign key, not the other way around.
Good point; I'll change this. Your second sentence is not exactly true. Just
to clarify, key assignments are based on job title and extracurricular duties
(coaching, tutoring, special projects, etc.). Masters allow all access per
location. So one key may open one or many doors. As I stated previously, you
are correct about the room type and wing being attributes of the room. Why
not "Campus"?>
In addition, the stadium and storage rooms do not have a room #, nor does it
belong to a wing. Do I need additional tables for this?
IMO this table is unecessary. Whether an employee is "full time" or
"temporary" is just an attribute that would go in tblEmployees. The fact
that a person may come and go as a member of your staff is irrelevant
to the fact that that person was in posession of a certain key at a
certain time. The date that a key was issued/returned belongs in
tblKeysEmployees.
I don't understand. If I add the substitute staff to the our employee table,
most of the fields will be empty. They are not required to disclose their
address or emergency info. There address is on file with the district. In
addition, they are not bound to teach any subject in particular. If there is
a request for a P.E. instructor but they normally teach English, they are
free to accept the position for the time requested. This is why I am adding a
"Preferred Subject" field. I want the sub to enjoy there time teaching and
the permanent staff to feel comfortable with whomever is taking over their
class. I am often asked for recommendations; I'd like some info to go along
with that. If we have a long-term position for a Special Education
instructor, I need to know who has that credential so we can move ASAP. Oddly
enough, the district doesn't track this info; I've asked. If I have the subs
in their own table, I think all the info I need will be together.
You might be thinking "great, now I have to add more tables" but keep
in mind that in an application like this you will typically have several
tables
that will basically just be "lookup" tables. They aren't really a big
deal to set up.
(lol) That is *exactly* what I was thinking!
You may also need some additional junction tables, depending on if - as
I stated earlier - an instructor can teach more than one subject, work in
more than one department, etc.
(heavy sigh...as my head hits the desk) Which ones? tblSubjects?
For you first app, you didn't exactly pick a simple one, but everyone loves
a challenge, right? <g>
Thank you for saying that! I kept wondering,"Why am I having such a hard
time with this?" Why am I still on the pen, paper and diagram stage?
I like a challenge because it makes success that much sweeter but *come
on*...! It makes it difficult to make a move when you are about ready to step
off the cliff at every turn. If it weren't for this discussion group, I would
have. Thanks to both you and Bruce for posting your reasons and thought
process along with your comments. I don't know about others, but it helps me
to follow along. I t takes an extra measure of patience that I appreciate. I
am going to rethink my tables and post them again. I hope you will take a
look and tell me what you think.
 
B

Beetle

Sorry if my reply came off kind of negative. I didn't mean to be.
You make some valid points about subjects and departments, and about titles
too if somebody holds more than one. I'm not sure exactly what is meant by
classification, so I couldn't say if there could be more than one. It
depends in part on how they do things. However, the posting was about keys,
so correctly or not I chose not to get into a discussion of the Employee
table.
I sort of knew you were trying to focus more on the keys, so when the OP
said they were satisfied with the Employees table I wanted them to at
least take another look at it and give it some more thought before moving on.
You may be correct about the RoomID as the FK. However, it isn't
necessarily as simple as a key opening a room (period). The building could
have a key, for instance, or there could be a padlock or other lock that is
not a room (or supply closet) lock. The OP said they don't "really" track
file cabinet keys and such, but if they ever have a key to something other
than a room provisions will need to be made for that. This is why I
suggeested a Locks table. A lock could have several keys. A Locks table
would need to specify the lock's location in a way that does not necessarily
reference a room (in what room is a building's front door located?). Also,
a room having several different locks (in an auditorium, for instance, or a
room with an outside door and a hallway door) is not out of the question.
I should have re-worded this part of my response, as I can see now that
it does not get my point across very well. I actually agree with you about the
locks. What I was trying to do was get the OP to realize that things like
Room Type, etc. are not attributes of the key. All a key does is - as you
correctly point out - open a particular lock. Where that lock is located is
an attribute of the lock, not the key.

Again, apologies if I came across as if I was saying you were wrong, that
wasn't my intention.

Regards,

Sean Bailey
 
B

BruceM

The curious thing was that you were replying to me without including my
wording, but in any case no offense taken.

I see from another posting that the OP has recognized some rethinking of the
Employee table may be in order. I built an Employee table for one
application, then ended up using it for others, so I can attest that a
well-designed table is a worthwhile investment of time. I say this because
my first attempt was not as well-designed as it might have been, so other
applications had to be updated in some cases.

Other comments in the OP's most recent reply show a growing realization
about other design elements. It was certainly a lot of project for a first
attempt. I expect the full extent wasn't really known at the time.
 
B

Beetle

Does school data need an additional table based solely on instuctors
teaching more than one subject? You are correct though. Teachers can teach
more than one subject. I only ask because you said, "additionally", which
implies that this will need a new table regardless. Other than "Subject", I
don't understand how I would be entering the same information again and
again. What am I missing?
In my opinion it should be in separate tables regardless. I don't know
how Classification and Title relate to your employees, so for now I'll
use Dept. Name and Subject as examples. As your table is currently
designed, each time you enter an employee record the user will have
to manually type in the Dept. Name and Subject. This is not only extra
work, it also invites spelling errors and invalid data in your table. The
correct way is to have separate "lookup" tables that store all possible
Departments and Subjects. These would be very simple tables that would
likely just have a few fields like;

DeptID
DeptName

SubjectID
SubjectName

Then you would use DeptID and SubjectID as foreign keys in other tables.
In your data entry forms, you would typically use combo boxes to allow
users to select the correct Dept./Subject from the list of choices.

Which tables should DeptID/SubjectID go in? Good question. I think this is a
very important part of your application that you have not completely
defined yet. In a relational database like Access, it is not only imerative
that
you determine what relationships you have, but what *type* each relationship
is. Is it One-to-Many? Is it Many-to-Many? If it is 1:m, then the PK field
from the "One" side table goes in the "Many" side table as a foreign key. If
it is m:m, then you need a third (junction) table to define the relationship,
like your
tblKeysEmployees. You said a teacher can teach more than one subject,
and, presumably, a subject can be taught by more than one teacher, so
this relationship is m:m. Therefore, you not only need another table to
define the list of available subjects, but also a junction table to define
the relationship.
Point taken; although I don't understand why the campus location is not a
room attribute. I need to know where that room or storage room is
located(especially since storage rooms don't have room #s). Does it make a
difference if there are only 2 campuses? No? So, is it CampusID (FK to
tblRooms)? Same for tblWings?
Also, I meant to put KeyType (Storage, Classroom, Gate Master, Grand Master,
etc.) as a field here.
As I stated in my reply to Bruce, I don't think I worded this part of my reply
very well. I was trying to point out that things like RoomType are not
attributes
of a key. I actually think bruce is right about this. When you break things
down
to lowest common denominator, all a key does is open a lock (or many locks if
it is a master key). Where that lock is located is an attribute of the lock,
not the key. As far as whether the Campus is an attribute of the Room? Maybe
it should be, I don't know enough about your app to say for sure. My train
of thought in my previous reply wasa basically the following;

A Campus would usually encompass more than one building, a building
may have more than one wing, and a wing may have more than one room.
So, again, if we break it down to LCD (so to speak) a room is only indirectly
related to a Campus, it's direct relationship would the wing in which it is
located (or perhaps the building if that building has no "wings"). However,
as Bruce correctly pointed out, what we are really talking about is locks,
so it should probably be broken down to that level.
Good point; I'll change this. Your second sentence is not exactly true. Just
to clarify, key assignments are based on job title and extracurricular duties
(coaching, tutoring, special projects, etc.). Masters allow all access per
location. So one key may open one or many doors.
I hadn't thought about Master keys. You may want to consider a separate table
for those, since they have a different type of relationship with the locks
than
the regular keys.
I don't understand. If I add the substitute staff to the our employee table,
most of the fields will be empty. They are not required to disclose their
address or emergency info. There address is on file with the district. In
addition, they are not bound to teach any subject in particular. If there is
a request for a P.E. instructor but they normally teach English, they are
free to accept the position for the time requested. This is why I am adding a
"Preferred Subject" field. I want the sub to enjoy there time teaching and
the permanent staff to feel comfortable with whomever is taking over their
class. I am often asked for recommendations; I'd like some info to go along
with that. If we have a long-term position for a Special Education
instructor, I need to know who has that credential so we can move ASAP. Oddly
enough, the district doesn't track this info; I've asked. If I have the subs
in their own table, I think all the info I need will be together.
OK, I can see where that is a little tricky. Still, I think I would just
list them
in the employee table and live with a few empty address fields. If you have
them in a separate table, then you're going to have to add another FK
field to your tblKeysEmployees, so either way you end up with empty fields
in one of your tables.
Thank you for saying that! I kept wondering,"Why am I having such a hard
time with this?" Why am I still on the pen, paper and diagram stage?
I like a challenge because it makes success that much sweeter but *come
on*...! It makes it difficult to make a move when you are about ready to step
off the cliff at every turn. If it weren't for this discussion group, I would
have. Thanks to both you and Bruce for posting your reasons and thought
process along with your comments. I don't know about others, but it helps me
to follow along. I t takes an extra measure of patience that I appreciate. I
am going to rethink my tables and post them again. I hope you will take a
look and tell me what you think.
Yeah, you kind of jumped right into the deep end of the pool, but hopefully
with help from the group here you'll get it all sorted out. You'll get
differing
opinions from people too, so sometimes you just have to absorb the different
ideas and then decide what you think will work best for you.
 
A

Aria

I have read and reread your comments and suggestions. I am commenting on the
following:
In my opinion it should be in separate tables regardless. I don't know
how Classification and Title relate to your employees, so for now I'll
use Dept. Name and Subject as examples. As your table is currently
designed, each time you enter an employee record the user will have
to manually type in the Dept. Name and Subject. This is not only extra
work, it also invites spelling errors and invalid data in your table.
....and the light goes on. Of course! How could I have missed *that*?!
Which tables should DeptID/SubjectID go in? Good question. I think this is a
very important part of your application that you have not completely
defined yet. In a relational database like Access, it is not only imerative
that
you determine what relationships you have, but what *type* each relationship
is.
I follow you. That was a great explanation. I understand and will be
thinking about this further.
A Campus would usually encompass more than one building, a building
may have more than one wing, and a wing may have more than one room.
So, again, if we break it down to LCD (so to speak) a room is only indirectly
related to a Campus, it's direct relationship would the wing in which it is
located (or perhaps the building if that building has no "wings"). However,
as Bruce correctly pointed out, what we are really talking about is locks,
so it should probably be broken down to that level.
Again, I follow what you're saying and having had time to think about all of
the information that both you and Bruce pointed out, I agree. He is correct.
He also threw in a monkey wrench. I did not want to hear about a Locks table
when I was having trouble with the tables I already have. But he posted
something in his reply that just knocked the wind out of me, but it opened my
eyes to see what he was saying.
I hadn't thought about Master keys. You may want to consider a separate table
for those, since they have a different type of relationship with the locks
than
the regular keys.
MasterKeys
MasterID
EmpID
KeyID (FK to tblKeys)?
OK, I can see where that is a little tricky. Still, I think I would just
list them
in the employee table and live with a few empty address fields. If you have
them in a separate table, then you're going to have to add another FK
field to your tblKeysEmployees, so either way you end up with empty fields
in one of your tables.
Huh? tblKeysEmployees? Not KeyID (FK to tblKeys)? You know I don't know what
it is about this table that makes me want to keep it. I respect your opinion
and will probably rue the day that I didn't follow your advice; especially if
I have to post back and have someone extricate me from my own dumb mistake
(be kind if that happens!). After all, I came here for advice. I think it's
all of the empty fields that I'm going to have. They bother me. They won't
need the inactive field or the "Subject", "Address", or all of the Emergency
Contact info (Hospital, Emergency Contact, Medications, Allergies, etc.) I'm
still thinking about this one.
Again, my sincerest thanks for your help. This has been eye-opening. Both
you and Bruce have shown me how to think about some of these problems in a
different way. You both pan wide and then zoom in on the tiny details that
are easily overlooked by novices. It's easy to answer the cut and dry
questions. But someone who takes on a rock bottom beginner and walks you step
by step through the process...well, that's extra special.
 
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A

Aria

Bruce,
A lock could have several keys.
True.

If a supply closet has three keys issued
and a fourth person needs a key, you need to know that another key has to be
made.
*Very* true.

The keys is an attribute of the lock, not the other way around.
At least that's how I see it.
I'm beginning to see what you mean here.

If a lock is changed you need a way to find the
existing keys so they can be swapped with the new ones.
(stunned silence)
You have my attention. This is exactly the situation we encountered this
school year. Someone who had a master key was working at our site one
weekend. The key was "lost". The decision was made to re-key an entire
campus; every single room and door. The locksmith and I worked well together.
It was a smooth process that took well over a month and a half to complete;
but we both suffered abuse. This is not a situation I care to repeat.
I see your point. Because our system is handwritten cards, I had no way of
knowing who had what key unless I was given a name and could look it up. This
was totally inadequate. I didn't mean to dismiss your idea out of hand, but I
loathed the idea of adding another table to the database since I was having
problems with the ones I currently have.

So, should it look like this:

tblLocks
******
LockID (PK) Autonumber
KeyID (FK to tblKeys)
RoomID (FK to tblRooms)
Campus-text
Wing-text
RoomType-text

If not, can you help me? I understand about I will need look-up tables. Not
quite sure how all of this will fit together.
I am going through all of the information that you and Beetle have given me.
I want to say to you as I posted to him, my sincerest thanks for all of your
help. To take on a novice and patiently give suggestions and explain your
thinking process in a step by step manner, is not only appreciated but very
special.
 
B

Beetle

Huh? tblKeysEmployees? Not KeyID (FK to tblKeys)?

Yes tblKeysEmployees because that is the table that is used to track which
employee has which key at a given time. If you put KeyID in tblSubs to
assign keys to subs, then you have the same problem you had with
tblEmployees. A sub will use more than one key, so you have to add
additional records for the same sub.

So you have to add another field in tblKeysEmployees as a foreign key
to tblSubs. You can't use the existing EmployeeID FK because subs
wouldn't exist in that table. So now you have at least one empty field
for *every* record in tblKeysEmployees (either EmployeeID or SubID
would be an empty field). That's what I mean when I say you end up
with empty fields either way.

However, there is a way to solve both problems, which I should have
mentioned in my last post, but it involves - yes, that's right -
ANOTHER TABLE...AAAAARRRRGGGGHHH! <g>

You reduce tblEmployees to only those fields that apply to *all* personell
(full time and subs), then you add another table for the data that
applies to only *some* employees, and relate it back via EmployeeID.

Serenity Now!<g>
 
A

Aria

Another table?! Scrap the whole thing; I'm going to do tblTours or
Products/Orders just like in the books! (lol)

Ok, ok, it's a done deal! I'll change it as suggested. I like this idea much
better. You have a fantastic day! I will be knee deep in all the posts that I
printed out; rewriting my notes and diagramming my structure.
 
B

BruceM

Your tblLocks is heading in the right direction. Let me suggest LocationID
rather than RoomID (in case the lock is to a building or a stadium or
something), and tblLocations instead of tblRooms. You could have a field in
tblLocations to identify the Location type (Room, Closet, etc.). Wing,
Campus, etc. are attributes of the Location. If you have linked to
tblLocations, all of the information in tblLocations is available (including
Wing, etc.). No need to store such items in the Locks table.

It would probably be best to keep a single thread going. Beetle and I may
end up saying the same thing, or slightly different things about the same
topic, in the two branches of this thread. Since there is more information,
including discussions of master keys and other matters, in the other thread,
let's keep the discussion there.
 
A

Aria

I'd like to address this part of your post 1st, Bruce:

It would probably be best to keep a single thread going. Beetle and I may
end up saying the same thing, or slightly different things about the same
topic, in the two branches of this thread. Since there is more information,
including discussions of master keys and other matters, in the other thread,
let's keep the discussion there.

....as you wish. I confess my ignorance here; all of this is new to me
(Access and posting). Before I was referred here by someone in my district, I
had never heard of a newsgroup/discussion group before. I had never posted
anywhere at anytime. I didn't realize I was creating additional threads. I
think I may have messed up this thread too. I'm just not sure how all of this
is supposed to work. I read the Getting Started section and read a lot of
posts before launching my own but... My apologies for any confusion I may
have caused.

Your tblLocks is heading in the right direction. Let me suggest LocationID
rather than RoomID (in case the lock is to a building or a stadium or
something), and tblLocations instead of tblRooms. You could have a field in
tblLocations to identify the Location type (Room, Closet, etc.). Wing,
Campus, etc. are attributes of the Location. If you have linked to
tblLocations, all of the information in tblLocations is available (including
Wing, etc.). No need to store such items in the Locks table.

I think your suggestion is perfect and rectifies the limitations encountered
with tblRooms. I have made the changes and am working on incorporating this
into the db.

Update-
Upon further reflection, I have scrapped tblSubs. No one cared for that
table except me.(smile) I thought it made sense, but I don't have any
experience in this area so I defer to your judgement and suggestions.
I am continuing to have problems with tblEmployees. It seemed so
straightforward in the beginning but now...additional issues keep popping up.
Before yesterday, I would have said that staff can only hold a single title.
I have thought of several situations where this is not true. If I have this
right, it would be a many-to-many relationship and requires a junction table.
Let me know if I've stepped off the cliff here.
I had to add a phone table because there are a possiblity of 3 phone #s that
a staff member may have aside from the room phone#, which I moved to
tblLocations per our previous discussion. I think this is a 1:M relationship.
We also discussed department affiliation but I can't recall an instance
where staff will belong to more than one department.
The Employee section of the db seems to be expanding. I'm still struggling
to work it out. As far as I can see, there seems to be some 1:1
relationships. As it stands now, there are at least 3 junction tables. One
thing is clear though, no matter how I work this, there will be empty fields
in some of the tables. I guess I *am* going to have to live with it.
 
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B

BruceM

You're doing fine with newsgroup etiquette and all that. I suggested a
single thread only because it may be easier for all involved. More comments
inline.

Aria said:
I'd like to address this part of your post 1st, Bruce:

It would probably be best to keep a single thread going. Beetle and I may
end up saying the same thing, or slightly different things about the same
topic, in the two branches of this thread. Since there is more
information,
including discussions of master keys and other matters, in the other
thread,
let's keep the discussion there.

...as you wish. I confess my ignorance here; all of this is new to me
(Access and posting). Before I was referred here by someone in my
district, I
had never heard of a newsgroup/discussion group before. I had never posted
anywhere at anytime. I didn't realize I was creating additional threads. I
think I may have messed up this thread too. I'm just not sure how all of
this
is supposed to work. I read the Getting Started section and read a lot of
posts before launching my own but... My apologies for any confusion I may
have caused.

Your tblLocks is heading in the right direction. Let me suggest LocationID
rather than RoomID (in case the lock is to a building or a stadium or
something), and tblLocations instead of tblRooms. You could have a field
in
tblLocations to identify the Location type (Room, Closet, etc.). Wing,
Campus, etc. are attributes of the Location. If you have linked to
tblLocations, all of the information in tblLocations is available
(including
Wing, etc.). No need to store such items in the Locks table.

I think your suggestion is perfect and rectifies the limitations
encountered
with tblRooms. I have made the changes and am working on incorporating
this
into the db.

Update-
Upon further reflection, I have scrapped tblSubs. No one cared for that
table except me.(smile) I thought it made sense, but I don't have any
experience in this area so I defer to your judgement and suggestions.
I am continuing to have problems with tblEmployees. It seemed so
straightforward in the beginning but now...additional issues keep popping
up.
Before yesterday, I would have said that staff can only hold a single
title.
I have thought of several situations where this is not true. If I have
this
right, it would be a many-to-many relationship and requires a junction
table.
Let me know if I've stepped off the cliff here.
You could have a Titles table and an Employees table, with a EmployeeTitle
junction table. That may make some sense if several employees have the same
title, but if a lot of titles are unique that approach could become awkward.
My thinking is that there would be a main form based on tblEmployees, with a
subform based on the junction table. The subform would have a combo box
based on tblTitles. However, if a title is not in tblTitles it would need
to be added before it can be selected from the combo box. That process can
be made fairly efficient and simple to perform, but if there is a frequent
need to add a title to tblTitles (because most titles are unique) it could
become tedious. Another approach would be that tblEmployeeTitle not be a
junction table, but rather that it be related one to many from tblEmployees
(one employee: several titles). Base a combo box on tblTitles, and store
the actual title in tblEmployeeTitle. Set Limit To List to No for the combo
box, and type in a title if it is not in tblTitles (or use the Not In List
event to add it to tblTitles). Again, it depends on the situation. If you
would like to do something such as generate reports that list employees by
title, the junction table is probably the best way to go (or the most
flexible, at least).
You may do well to start a new thread on this specific topic. I'm not sure
I have the experience to advise you confidently that one choice is better
than another in a particular situation. The thing is that this database is
about keys, but once you have an Employee table you will probably use it
again and again (as a linked table in other projects), so it is well to
design it as carefully as can be done.
I had to add a phone table because there are a possiblity of 3 phone #s
that
a staff member may have aside from the room phone#, which I moved to
tblLocations per our previous discussion. I think this is a 1:M
relationship.
One employee: several phones is one-to-many, but if a phone could have
several people answering it, depending on the time of day, you may need a
jPhonePerson unction table. StartTime and EndTime may be fields in the
junction table for the room phones. Ideally this would be linked to
scheduling, so that a class schedule would indicate when an employee could
be reached at a particular room phone (or something like that), but that
could become quite complex.
We also discussed department affiliation but I can't recall an instance
where staff will belong to more than one department.
If so, you could just store the department in tblEmployees. However, be
sure of this, as it is moredifficult to rearrange the database later.
The Employee section of the db seems to be expanding. I'm still struggling
to work it out. As far as I can see, there seems to be some 1:1
relationships. As it stands now, there are at least 3 junction tables. One
thing is clear though, no matter how I work this, there will be empty
fields
in some of the tables. I guess I *am* going to have to live with it.
What 1:1 relationships? There are valid reasons for using these, but they
could also just serve to make things complicated.
 
B

Beetle

The Employee section of the db seems to be expanding. I'm still struggling
to work it out. As far as I can see, there seems to be some 1:1
relationships. As it stands now, there are at least 3 junction tables. One
thing is clear though, no matter how I work this, there will be empty fields
in some of the tables. I guess I *am* going to have to live with it.
One-to-One relationships are less common than 1:m and m:m, but in your
case it may very well be applicable. They are typically used when you
are sub-typing. The following is an excerpt from a recent post by resident
guru Ken Sheridan that talks about this type of relationship (I couldn't
possibly explain it any better). Hopefully he won't mind that I reposted his
comments. The thread in question is about setting up a Church db, so
you will see references to the Church of England etc., but the concept
may be helpful in your situation.

***************************************************

When it comes to people connected to the church in some way or other things
get a little more complex, but not frighteningly so, as the principles
involved are quite simple. All people share certain attribute types of
course; we all have names, an address, a date of birth and so on. So there
is an entity type People with these common attribute types, and a table can
represent this attribute type. People with different roles may well have
attribute types which are specific to their role, e.g. a pastor is likely to
have attribute types which a member of his congregation would not have. If I
can use an example from the C of E an attribute type for a C of E priest
might be Date of Ordination. So the entity type Pastors is a sub-type of the
entity type People. The way a sub-type is modelled in a relational data base
is by means of a one-to-one relationship. In the case of People and its
sub-type Pastors this would mean that there would be a table people with a
numeric primary key PersonID (don't use names as a primary key, they can be
duplicated), and a Pastors table also with a numeric primary key PersonID
(you can call it PastorID if you wish, but I prefer to keep the column names
the same). In the case of the Pastors table PersonID would also be a foreign
key referencing the primary key of People. The people table would have
columns for the common attributes like names and address etc., the Pastors
table would have columns only for those attribute type specific to the
Pastors entity type, e.g. Date of Ordination, but not the common attributes
like names and address.

A sub-type can of course have sub-types of its own; Chris Date in one of his
books gives the example of a type Employees with sub-type programmers, and
sub-types of programmers, System programmers and Application programmers.

As far as the primary keys are concerned, if you use an autonumber column
you can only do so for the topmost type, e.g. you could have an autonumber
PersonID column in the People table, but the primary key of Pastors or other
sub-type of people must be a straightforward long integer number data type,
not an autonumber.

When it comes to events connected with a church you need to think carefully
about how these fit into the model. One thing you need to be careful of is
deciding whether an event type is a sub-type of another type, or whether the
type of an event is an attribute type of a single entity type. You might
have a topmost Events entity type with attribute type such as Event Date,
Location etc and a Baptisms sub-type with attribute types such as ChildID,
FatherID, MotherID, all three referencing the People table. Another way of
modelling it would be to have a single Events table with an attribute type
EventType, in which a value 'Baptism' would be entered. The problem with the
latter approach of course is that if you also have ChildID, FatherID,
MotherID columns these won't be appropriate to other types of events in the
same table. In this case therefore a type/sub-type model is probably the
most appropriate. In the case of other entity types, however, the second
approach might be more suitable. To take an extreme example, in a personnel
database you would not have an Employees table and a separate table for every
Job Title in the organization; you'd be more likely to have a Positions table
and an EmployeeHistory table with EmployeeID, PositionID, DateFrom and DateTo
columns to model the many-to-many relationship between Employees and
positions.

****************************************************

Hopefully this will help you. If you still have questions, as Bruce said it
may be helpbul to start a new thread. He and I may be the only ones
still following this thread. If you need to repost, it may be helpful if
you include some more detailed information about your Employees table
such as;

1) What different types of employees you need to track

2) Which attributes are common to *all* employees

3) Which attributes are specific to only certain employees.
 
A

Aria

First, let me say,"WOW"! You both have given me *so much* information. Thank
you! My comments are below (I'm combining posts. I didn't know how else to do
this):
Bruce M:
You could have a Titles table and an Employees table, with a EmployeeTitle
junction table. That may make some sense if several employees have the same
title, but if a lot of titles are unique that approach could become awkward.
My thinking is that there would be a main form based on tblEmployees, with a
subform based on the junction table.

Aria:
Do I need a subform if the majority of the staff only hold one title? Yes, I
still trying to get over having empty fields but I haven't made it this far
so I don't know. The form I envision would have this info on the main form
using a combobox for the titles. I am trying to think of every possible title
that I can. I don't want any suprises here.

Bruce M:

If you would like to do something such as generate reports that list
employees by
title, the junction table is probably the best way to go (or the most
flexible, at least).

Aria:
That is exactly what I want to do; grouped by title. I think I'll do the
junction table.

Bruce M:
You may do well to start a new thread on this specific topic. I'm not sure
I have the experience to advise you confidently that one choice is better
than another in a particular situation.

Aria:
I know I'm struggling but sometimes that's o.k. (I can't believe I said
*that*!) Let me qualify that remark by saying it depends on the hour. I know
I need to learn how to figure out some of these issues myself. I have to try
first. If I continue to have problems, I will of course follow your advice
(you and Beetle).

Bruce M:
The thing is that this database is about keys, but once you have an Employee
table you will probably use it again and again (as a linked table in other
projects), so it is well to
design it as carefully as can be done.

Aria:
Absolutely!!! You know our history here (some bad memories). Keys are
problematic for us. I have always said that I don't mind putting in the hard
work at the beginning so that it will seem effortless in the end. Well, here
it is. I am willing to put in the effort but some days I am frustrated beyond
belief.
I had to add a phone table because there are a possiblity of 3 phone #s
that
a staff member may have aside from the room phone#, which I moved to
tblLocations per our previous discussion. I think this is a 1:M
relationship.
Bruce M:
One employee: several phones is one-to-many, but if a phone could have
several people answering it, depending on the time of day, you may need a
jPhonePerson unction table. StartTime and EndTime may be fields in the
junction table for the room phones. Ideally this would be linked to
scheduling, so that a class schedule would indicate when an employee could
be reached at a particular room phone (or something like that), but that
could become quite complex.

Aria:
Whew! Thank goodness I don't have to worry about that. A room phone could
have several people answer it. This will depend on who is assigned to the
room. The good thing is that they don't roam. All bets are off for the
upcoming school year though. I've heard rumors. I should be getting a room
assignment list from the Principal soon. We'll see....

Aria:
We also discussed department affiliation but I can't recall an instance
where staff will belong to more than one department.
Bruce M:
If so, you could just store the department in tblEmployees. However, be
sure of this, as it is moredifficult to rearrange the database later.

Aria:
Ugh! Nooooooo...I was so sure! I checked over and over and over again and
last night I finally found it...one person, two departments. Will this never
end?!


Beetle said:
One-to-One relationships are less common than 1:m and m:m, but in your
case it may very well be applicable. They are typically used when you
are sub-typing. The following is an excerpt from a recent post by resident
guru Ken Sheridan that talks about this type of relationship (I couldn't
possibly explain it any better). Hopefully he won't mind that I reposted his
comments. The thread in question is about setting up a Church db, so
you will see references to the Church of England etc., but the concept
may be helpful in your situation.
Thank you! I am familiar with Mr. Sheridan's posts. Wow, there is a lot of
information there. I had to really pay attention though and relate it to my
situation. After reading it, I'm not as frustrated. Yes, there are 1:1
relationships here but it may be what I need. I do think that I have
sub-types. Let me work with this some more before I let you both know which
1:1 relationships I have.
A sub-type can of course have sub-types of its own; Chris Date in one of his
books gives the example of a type Employees with sub-type programmers, and
sub-types of programmers, System programmers and Application programmers.
Great...I think I have at least one situation where this is true.
As far as the primary keys are concerned, if you use an autonumber column
you can only do so for the topmost type, e.g. you could have an autonumber
PersonID column in the People table, but the primary key of Pastors or other
sub-type of people must be a straightforward long integer number data type,
not an autonumber.
To take an extreme example, in a personnel database you would not have an Employees > table and a separate table for every Job Title in the organization; you'd be more likely to > have a Positions table and an EmployeeHistory table with EmployeeID, PositionID, >DateFrom and DateTo columns to model the many-to-many relationship between >Employees and positions.
Hey, perfect example!
Hopefully this will help you. If you still have questions, as Bruce said it
may be helpbul to start a new thread. He and I may be the only ones
still following this thread.
It does help. Thank you for that. I want to continue trying before I throw
in the towel and ask for help.

Comments for both of you:
1. You two are *great* teachers who always give me homework! There is such a
wealth of information, instructions and suggestions that you put into your
replies that I can't post back right away; I'm studying, highlighting and
taking notes! :)

2. I've learned SO much from you (the collective you). I consider myself
incredibly fortunate that you responded to my post.

3. I have varying degrees of frustration and confusion. I'm confused by some
of my own table names (yeah, I know that doesn't even begin to make sense to
you. I'll work on more logical naming). :)
I'm also confusing myself by thinking to hard and long about some of these
issues. I know the answer is right in front of me but I can't see it.

4. Like I said before, you both pan wide and then zoom in, incrementally, to
get to the crux of a problem. I want to do that. This is starting to come
into focus a little more now. I just have to keep reminding myself that
problems I encounter now, will be be something I won't have to deal with
later after everything is set. It's frustrating but I'm trying to keep it in
perspective.

5. See #3. I'm going to have to take a step back. I have been working on
this day and night (in between my day job). I have been thinking about
database design in my sleep (I know, I've got it bad).
6. I have taken up so much of your time already. You have moved me forward
by leaps and bounds. I understand that there are others who need help too.
Thank you for being here to answer all of my questions. I know my posts
aren't the normal kind (a bazillion questions all at once). You have both
been so kind and patient and have not yelled at me once (yes, I did have that
fear when I posted). You have no idea how dejected I was when I first posted,
but every question answered unraveled the knot just a little bit more. I'm
going to take a couple of days and see if I can work out this employee table.
When I return, I would like to get back to tblLocations, tblKeys, etc. I hope
you will still be here, but if not, I completely understand.

I just wanted you to know how grateful I am. I'm sure this is more than you
*ever* wanted to know about locks, keys and school "issues".
 
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B

BruceM

What a wonderfully gracious reply. Thank you for your kind words.

I know you said you are going to work on this for a few days, but here are a
couple of thoughts anyhow. For the phone table you may want to add a
time-of-day field. I gather that updating such information is a once per
year chore, which would be a simpler task than trying to tie in the phone
numbers with a schedule, particularly since you aren't using the dtabase for
scheduling.

A sort of standard example of a one-to-one relationship is a company
softball team. A SoftballTeam table may contain information that is not in
the main Employee record, so it is set apart in its own table. An employee
would only be in the SoftballTeam table once, and likewise an employee on
the softball team will have just one corresponding record in the main
Employee table.
 

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