OdbcTransaction.Rollback Method
Definition
Important
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Rolls back a transaction from a pending state.
public:
override void Rollback();public:
virtual void Rollback();public override void Rollback ();public void Rollback ();override this.Rollback : unit -> unitabstract member Rollback : unit -> unit
override this.Rollback : unit -> unitPublic Overrides Sub Rollback ()Public Sub Rollback ()Implements
Exceptions
An error occurred while trying to commit the transaction.
The transaction has already been committed or rolled back.
-or-
The connection is broken.
Examples
The following example creates an OdbcConnection and an OdbcTransaction. It also demonstrates how to use the BeginTransaction, Commit, and Rollback methods.
public static void ExecuteTransaction(string connectionString)
{
using (OdbcConnection connection =
new OdbcConnection(connectionString))
{
OdbcCommand command = new OdbcCommand();
OdbcTransaction transaction = null;
// Set the Connection to the new OdbcConnection.
command.Connection = connection;
// Open the connection and execute the transaction.
try
{
connection.Open();
// Start a local transaction
transaction = connection.BeginTransaction();
// Assign transaction object for a pending local transaction.
command.Connection = connection;
command.Transaction = transaction;
// Execute the commands.
command.CommandText =
"Insert into Region (RegionID, RegionDescription) VALUES (100, 'Description')";
command.ExecuteNonQuery();
command.CommandText =
"Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')";
command.ExecuteNonQuery();
// Commit the transaction.
transaction.Commit();
Console.WriteLine("Both records are written to database.");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
try
{
// Attempt to roll back the transaction.
transaction.Rollback();
}
catch
{
// Do nothing here; transaction is not active.
}
}
// The connection is automatically closed when the
// code exits the using block.
}
}
Public Sub ExecuteTransaction(ByVal connectionString As String)
Using connection As New OdbcConnection(connectionString)
Dim command As New OdbcCommand()
Dim transaction As OdbcTransaction
' Set the Connection to the new OdbcConnection.
command.Connection = connection
' Open the connection and execute the transaction.
Try
connection.Open()
' Start a local transaction.
transaction = connection.BeginTransaction()
' Assign transaction object for a pending local transaction.
command.Connection = connection
command.Transaction = transaction
' Execute the commands.
command.CommandText =
"Insert into Region (RegionID, RegionDescription) VALUES (100, 'Description')"
command.ExecuteNonQuery()
command.CommandText =
"Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')"
command.ExecuteNonQuery()
' Commit the transaction.
transaction.Commit()
Console.WriteLine("Both records are written to database.")
Catch ex As Exception
Console.WriteLine(ex.Message)
' Try to rollback the transaction
Try
transaction.Rollback()
Catch
' Do nothing here; transaction is not active.
End Try
End Try
' The connection is automatically closed when the
' code exits the Using block.
End Using
End Sub
Remarks
The transaction can be rolled back only from a pending state (after BeginTransaction has been called, but before Commit is called). The transaction will be rolled back in the event it is disposed before Commit or Rollback is called.
