Question

I’m implementing an application using vb.net 2005 with Oracle 10g and I came across a functionality that should Select/Insert/Update/Delete data from three different tables in Oracle.

So I’m wondering if there is a way to prepare all the 3 commands (SQL Statements) separately and then execute them in one shot to the oracle, so in this way I can guarantee that all of them are successfully executed or all are failed to execute, and also I could gain more performance which is critical in my case.

Thus I’m looking for a syntax in vb.net that helps me execute more than one OracleCommand in one shot to the oracle.

Answer 1

This could be answered with a pseudocode

Dim cnn as OracleConnection
Dim tr as OracleTransaction 
Try
    cnn = new OracleConnection("your_connection_string")
    cnn.Open()
    tr = cnn.BeginTransaction(IsolationLevel.ReadCommitted)

    Dim cmd1 as OracleCommand = con.CreateCommand();
    Dim cmd2 as OracleCommand = con.CreateCommand();
    Dim cmd3 as OracleCommand = con.CreateCommand();

    cmd1.CommandText = "Your_Query_Text1"
    cmd2.CommandText = "Your_Query_Text2"
    cmd3.CommandText = "Your_Query_Text3"    

    cmd1.ExecuteNonQuery()
    cmd2.ExecuteNonQuery()
    cmd3.ExecuteNonQuery()

    tr.Commit()
    cnn.Close()
    cnn = Nothing
    tr = Nothing
Catch
   if tr <> Nothing then
       tr.Rollback()
   End if 
   If cnn <> Nothing Then 
       cnn.Close()
   End If
   cnn = Nothing
   tr = Nothing
End Try

A transaction makes the database perform a series of actions as a unit. You mark the start of a transaction calling the BeginTransaction method of your connection. Operations inside a transaction block are guaranteed to either all occur or all not occur.

If everything goes well, you confirm the transaction and everything is persisted in your tables. If something happens to interrupt your code flow (exceptions) you should call "rollback" to cancel everything you have done to the database while inside the transaction.