I would like to create my own primary key using a concatenation of existing
fields:
eventnumber & date & time.
How do I go about doing this?
Any help is greatly appreciated. Thank you in advance.

Why? Access is capable of using a primary key that's comprised of up to ten
separate fields.

Concatenating values into a single field is rarely a good idea.

--
Doug Steele, Microsoft Access MVP
http://I.Am/DougSteele
(no e-mails, please!)


"DGregg" <(E-Mail Removed)> wrote in message
news:BD804869-FD9D-473C-826B-(E-Mail Removed)...
>I would like to create my own primary key using a concatenation of existing
> fields:
> eventnumber & date & time.
> How do I go about doing this?
> Any help is greatly appreciated. Thank you in advance.
>
>

Thank you for your response. Perhaps I'm wording this incorrectly. I would
like to create a primary key (separate field, of course) that is comprised of
data in 3 existing fields: EventNumber, Date, Time. I'm not sure how to go
about doing this.

"Douglas J. Steele" wrote:

> Why? Access is capable of using a primary key that's comprised of up to ten
> separate fields.
>
> Concatenating values into a single field is rarely a good idea.
>
> --
> Doug Steele, Microsoft Access MVP
> http://I.Am/DougSteele
> (no e-mails, please!)
>
>
> "DGregg" <(E-Mail Removed)> wrote in message
> news:BD804869-FD9D-473C-826B-(E-Mail Removed)...
> >I would like to create my own primary key using a concatenation of existing
> > fields:
> > eventnumber & date & time.
> > How do I go about doing this?
> > Any help is greatly appreciated. Thank you in advance.
> >
> >
>
>
>

What Doug said.

I'll add that multi-field primary keys can be a PITA to maintain. If you
have a two-field PK, then you need a two-field foriegn key in related tables.

IMHO you are better off using an autonumber as the primary key and making
the two fields a unique index / constraint to prevent duplicates.

One other thing: Date and time should be in just one field. Again IMHO.
--
Jerry Whittle, Microsoft Access MVP
Light. Strong. Cheap. Pick two. Keith Bontrager - Bicycle Builder.


"DGregg" wrote:

> I would like to create my own primary key using a concatenation of existing
> fields:
> eventnumber & date & time.
> How do I go about doing this?
> Any help is greatly appreciated. Thank you in advance.
>
>

If you're doing it through the GUI, open the table in Design view and select
all of the fields of interest (using the Ctrl key if they're not
contiguous). Then, click on the Key button on the Button Bar (or select
Primary Key from the Edit menu)

--
Doug Steele, Microsoft Access MVP
http://I.Am/DougSteele
(no e-mails, please!)


"DGregg" <(E-Mail Removed)> wrote in message
news:31FCCD92-ADBF-430B-85EE-(E-Mail Removed)...
> Thank you for your response. Perhaps I'm wording this incorrectly. I
> would
> like to create a primary key (separate field, of course) that is comprised
> of
> data in 3 existing fields: EventNumber, Date, Time. I'm not sure how to
> go
> about doing this.
>
> "Douglas J. Steele" wrote:
>
>> Why? Access is capable of using a primary key that's comprised of up to
>> ten
>> separate fields.
>>
>> Concatenating values into a single field is rarely a good idea.
>>
>> --
>> Doug Steele, Microsoft Access MVP
>> http://I.Am/DougSteele
>> (no e-mails, please!)
>>
>>
>> "DGregg" <(E-Mail Removed)> wrote in message
>> news:BD804869-FD9D-473C-826B-(E-Mail Removed)...
>> >I would like to create my own primary key using a concatenation of
>> >existing
>> > fields:
>> > eventnumber & date & time.
>> > How do I go about doing this?
>> > Any help is greatly appreciated. Thank you in advance.
>> >
>> >
>>
>>
>>

Douglas, thank you for your response. This did the trick.

"Douglas J. Steele" wrote:

> If you're doing it through the GUI, open the table in Design view and select
> all of the fields of interest (using the Ctrl key if they're not
> contiguous). Then, click on the Key button on the Button Bar (or select
> Primary Key from the Edit menu)
>
> --
> Doug Steele, Microsoft Access MVP
> http://I.Am/DougSteele
> (no e-mails, please!)
>
>
> "DGregg" <(E-Mail Removed)> wrote in message
> news:31FCCD92-ADBF-430B-85EE-(E-Mail Removed)...
> > Thank you for your response. Perhaps I'm wording this incorrectly. I
> > would
> > like to create a primary key (separate field, of course) that is comprised
> > of
> > data in 3 existing fields: EventNumber, Date, Time. I'm not sure how to
> > go
> > about doing this.
> >
> > "Douglas J. Steele" wrote:
> >
> >> Why? Access is capable of using a primary key that's comprised of up to
> >> ten
> >> separate fields.
> >>
> >> Concatenating values into a single field is rarely a good idea.
> >>
> >> --
> >> Doug Steele, Microsoft Access MVP
> >> http://I.Am/DougSteele
> >> (no e-mails, please!)
> >>
> >>
> >> "DGregg" <(E-Mail Removed)> wrote in message
> >> news:BD804869-FD9D-473C-826B-(E-Mail Removed)...
> >> >I would like to create my own primary key using a concatenation of
> >> >existing
> >> > fields:
> >> > eventnumber & date & time.
> >> > How do I go about doing this?
> >> > Any help is greatly appreciated. Thank you in advance.
> >> >
> >> >
> >>
> >>
> >>
>
>
>

Thank you for your response, Jerry.

"Jerry Whittle" wrote:

> What Doug said.
>
> I'll add that multi-field primary keys can be a PITA to maintain. If you
> have a two-field PK, then you need a two-field foriegn key in related tables.
>
> IMHO you are better off using an autonumber as the primary key and making
> the two fields a unique index / constraint to prevent duplicates.
>
> One other thing: Date and time should be in just one field. Again IMHO.
> --
> Jerry Whittle, Microsoft Access MVP
> Light. Strong. Cheap. Pick two. Keith Bontrager - Bicycle Builder.
>
>
> "DGregg" wrote:
>
> > I would like to create my own primary key using a concatenation of existing
> > fields:
> > eventnumber & date & time.
> > How do I go about doing this?
> > Any help is greatly appreciated. Thank you in advance.
> >
> >