help with converting from VB4.0

  • Thread starter Thread starter jmarzion
  • Start date Start date
J

jmarzion

I am trying to convert an old VB4.0 application to VB.net and I am
pulling my hair out over understanding changes in database connections,
etc. I am using a ACCESS database.

In the old code, if I wanted to write to the database, I'd simply put
something like:

myDB = Workspaces(0).OpenDatabase("C:\productAPP\QuoteDB.mdb")
myTABLE = myDB.OpenRecordset("Quote Details", dbOpenTable)
myTABLE.LockEdits = False
myTABLE.AddNew() ' Create new record.
If modIDhold <> "" Then myTABLE("ModelID") = modIDhold ' Set record
key.
myTABLE("Qty") = itemQTY
myTABLE("PN") = itemPN
myTABLE("Description") = itemDESC
myTABLE("Price") = itemPRICE
myTABLE.Update() ' Save changes.
myTABLE.Close() ' Close Table.

Simple and straightforward, right? I have spent hours reading books
and websites trying to find a clear concise way of doing the same thing
in VB.net. Can someone out there please post code for doing the same
thing in VB.net. Please make the assumption that I (or someone else
who later reads this) knows nothing about VB.net. Looking for someone
who can explain this in easy-to-understand, common terms. Everything
I come across related to this topic makes me feel pretty inept...

Thanks in advance,

jmar
 
Cor,

I am using Visual Studio.Net 2003. I would appreciate if you could
make a peice of sample code based on mine.

Thanks.

Jmar
 
I should add that I'd rather do this in code than with the data
wizards. I prefer to understand how it works rather than just get it
to work.

Jmar
 
Jmar,

Because that it is your code. I could not test it.
However it would not be far from this.
The variables that I placed in it, do you have to change of course yourself
again.
And it is than your code without any error check. or correction on that.


\\\
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
Dim conn As New
OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;" & _
" Data Source=C:\ProductAPP\QuoteDB.mdb;User
Id=admin;Password=;")
Dim dt As New DataTable
Dim da As New OleDb.OleDbDataAdapter("Select * from Quote Details",
conn)
da.FillSchema(dt, SchemaType.Mapped)
Dim myTable As DataRow = dt.NewRow 'mytable is a datarow
myTable("ModelID") = "Whatever" 'Set record key.
myTable("Qty") = "itemQTY"
myTable("PN") = "itemPN"
myTable("Description") = "itemDESC"
myTable("Price") = "itemPRICE"
dt.Rows.Add(myTable)
Dim cmb As New OleDb.OleDbCommandBuilder(da)
da.Update(dt) ' Save changes.
End Sub
///

I hope this helps,

Cor
 
Great response Cor. Thank you! I was able to quickly and easily write
to the database using your help.

It leads to a few more questions:

1) What does the Dim cmb line do? I don't understand it.

2) More importantly, if I wanted to follow this code up with
additional code that writes to another table in the same database
(table name QTEMODEL), then how would I do this? If you could use the
above code and append to it, I'd be very grateful. I'm running
into a "row already exists" error. Do I somehow have to close
myTABLE before I start the next?

3) If I wanted to put several rows in one table (within a loop),
how would I change the above?

Once again, thank you, thank you, thank you!

Jmar
 
John,

If you want to Insert a record in a table and and you are sure it does not
exist, use than a SQL insert command. You will have to do a lot with those
transactions SQL commands.

This are nice pages on MSDN for Access

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnacc2k/html/acfundsql.asp

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnacc2k/html/acintsql.asp

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnacc2k/html/acadvsql.asp

To use those, you use an OleDB.Command.executeNonQuery

http://msdn2.microsoft.com/en-us/library/system.data.oledb.oledbcommand.executenonquery(VS.80).aspx

I have the idea that on that page is everything you needed.

Use a dataadapter and a datatable/dataset if you need the user to do
interactions with that.

I hope this helps,

Cor
 
Cor,

Excellent information. I can see that SQL commands are what I'm
looking for, I just don't know the syntax required to code them. Would
it be possible for you to revise the code you sent in Reply #4 and
incorporate the SQL so that I get a handle on the syntax? It would
help me to see it with my own code.

Thanks,

John
 
Would
it be possible for you to revise the code you sent in Reply #4 and
incorporate the SQL so that I get a handle on the syntax? It would
help me to see it with my own code.
Click to expand...
No John, I try you to teach you how to fish, I don't give the fish.

You have a start now, we all had to try.

Sorry,

Cor
 
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