ACC2000: Error Using CurrentProject.Connection in Transactions

ID: Q223213

The information in this article applies to:

Microsoft Access 2000

Advanced: Requires expert coding, interoperability, and multiuser skills.

This article applies to a Microsoft Access database (.mdb) and a Microsoft Access project (.adp).

SYMPTOMS

If you use the CommitTrans or RollbackTrans methods directly with the CurrentProject.Connection object, you may receive one of the following errors:

You tried to commit or rollback a transaction without first beginning a transaction.

-or-

No transaction is active.

CAUSE

Each time the CurrentProject.Connection object is used, it has a different pointer to the connection. In effect, the instance or pointer to that object is temporary. This is why you see no error on CurrentProject.Connection.BeginTrans, but you do receive an error once you try to commit or rollback the transaction.

RESOLUTION

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CAUTION: Following the steps in this example will modify the sample database Northwind.mdb. You may want to back up the Northwind.mdb file and perform these steps on a copy of the database.

Set an object variable once to CurrentProject.Connection and use it for your transaction processing, such as in the following example. Here, "c" is the Connection object used for transactions:

NOTE: The sample code in this article uses Microsoft ActiveX Data Objects. For this code to run properly, you need to reference the Microsoft ActiveX Data Objects 2.1 Library.

Open the sample database Northwind.mdb.

In the Database windows, click Modules under Objects, and then click New.

Type the following code in the new module:


Sub tstConnectionObj()

   Dim c As ADODB.Connection
   Dim rs As ADODB.Recordset

   Set c = CurrentProject.Connection
   Set rs = New ADODB.Recordset

   rs.Open "Categories", c, adOpenDynamic, adLockOptimistic

   c.BeginTrans
   rs.Fields(1) = "Drinks"

   rs.Update
   MsgBox "Updated field to " & rs.Fields(1) & "."

   c.RollbackTrans
   rs.Requery
   MsgBox "Rolled back field to " & rs.Fields(1) & "."

End Sub

In the Immediate window, type the following and press ENTER:
```
tstConnectionObj 
```
Note that you see the following message:

Updated field to Drinks.

Click OK on the message. Note that you see the following message:

Rolled back field to Beverages.

Click OK on the message.

MORE INFORMATION

Steps to Reproduce Behavior

Open the sample database Northwind.mdb.

In the Database windows, click Modules under Objects, and then click New.

Type the following code in the new module:


Sub tstCurrentProj()

   Dim rs As ADODB.Recordset

   Set rs = New ADODB.Recordset

   rs.Open "Categories", CurrentProject.Connection, adOpenDynamic, _
     adLockOptimistic

   CurrentProject.Connection.BeginTrans
   rs.Fields(1) = "Drinks"
   rs.Update
   MsgBox "Updated field to " & rs.Fields(1) & "."

   CurrentProject.Connection.RollbackTrans
   MsgBox "Rolled back field to " & rs.Fields(1) & ".

End Sub

In the Immediate window, type the following and press ENTER:
```
tstCurrentProj 
```
Note that you see the following message:

Updated field to Drinks.

Click OK on the message.

Note that you see the first error message mentioned in the "Symptoms" section of this article.

Additional query words: prb

Keywords :
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbprb