Question

I have a vb.net web app and I am passing a SQL connection and a transaction to a method which writes a single record to the database.

I would like to start and commit a transaction for each record that is written but using the same sql connection until the loop is done.

One method I saw was utilizing a using statement but it didn’t work for me.it runs the first time and gives an error on the second that the transaction has already been commited

Using sqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
  sqlConnection.Open()
  Using transaction = sqlConnection.BeginTransaction(IsolationLevel.ReadCommitted)

      For Each user In users
         Try
            myDataWriteMethod(user, conn, tr)

         Catch ex As Exception
            tranaction.rollback()
         End Try
         transaction.commit()
      Next 
    End Using
End Using  

Answer 1

It looks as if you are committing or rolling back the transaction at each step of the for loop. You probably need to either (1) begin a new transaction for each user, e.g.,

Using sqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
  sqlConnection.Open()
  For Each user In users
      Using transaction = sqlConnection.BeginTransaction(IsolationLevel.ReadCommitted)
      ...

or (2) only commit or rollback the transaction at the end, e.g.

Using sqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
  sqlConnection.Open()
  Using transaction = sqlConnection.BeginTransaction(IsolationLevel.ReadCommitted)

      Try
          For Each user In users
              myDataWriteMethod(user, conn, tr)
          Next
      Catch ex As Exception
          tranaction.rollback()
      End Try

      transaction.commit()
  End Using
End Using

Note that I’m not a VB.NET programmer so my syntax may be wrong.