Rolls back a transaction from a pending state.

The Rollback method is equivalent to the MySQL statement ROLLBACK. The transaction can only be rolled back from a pending state (after BeginTransaction has been called, but before Commit is called).

Examples

The following example creates MySqlConnection and a MySqlTransaction. It also demonstrates how to use the MySqlConnection.BeginTransaction, Commit, and Rollback methods.

Visual Basic example:

Public Sub RunSqlTransaction(myConnString As String)
    Dim myConnection As New MySqlConnection(myConnString)
    myConnection.Open()
    
    Dim myCommand As MySqlCommand = myConnection.CreateCommand()
    Dim myTrans As MySqlTransaction
    
    ' Start a local transaction
    myTrans = myConnection.BeginTransaction()
    
    ' Must assign both transaction object and connection
    ' to Command object for a pending local transaction
    myCommand.Connection = myConnection
    myCommand.Transaction = myTrans
    
    Try
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (100, 'Description')"
      myCommand.ExecuteNonQuery()
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (101, 'Description')"
      myCommand.ExecuteNonQuery()
      myTrans.Commit()
      Console.WriteLine("Success.")
    Catch e As Exception
      Try
        myTrans.Rollback()
      Catch ex As MySqlException
        If Not myTrans.Connection Is Nothing Then
          Console.WriteLine("An exception of type " & ex.GetType().ToString() & _
                            " was encountered while attempting to roll back the transaction.")
        End If
      End Try
    
      Console.WriteLine("An exception of type " & e.GetType().ToString() & _
                      "was encountered while inserting the data.")
      Console.WriteLine("Neither record was written to database.")
    Finally
      myConnection.Close()
    End Try
End Sub

C# example:

public void RunSqlTransaction(string myConnString) 
 {
    MySqlConnection myConnection = new MySqlConnection(myConnString);
    myConnection.Open();
    MySqlCommand myCommand = myConnection.CreateCommand();
    MySqlTransaction myTrans;
    // Start a local transaction
    myTrans = myConnection.BeginTransaction();
    // Must assign both transaction object and connection
    // to Command object for a pending local transaction
    myCommand.Connection = myConnection;
    myCommand.Transaction = myTrans;
    try
    {
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (100, 'Description')";
      myCommand.ExecuteNonQuery();
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (101, 'Description')";
      myCommand.ExecuteNonQuery();
      myTrans.Commit();
      Console.WriteLine("Both records are written to database.");
    }
    catch(Exception e)
    {
      try
      {
        myTrans.Rollback();
      }
      catch (MySqlException ex)
      {
        if (myTrans.Connection != null)
        {
          Console.WriteLine("An exception of type " + ex.GetType() +
                            " was encountered while attempting to roll back the transaction.");
        }
      }
    
      Console.WriteLine("An exception of type " + e.GetType() +
                        " was encountered while inserting the data.");
      Console.WriteLine("Neither record was written to database.");
    }
    finally 
    {
      myConnection.Close();
    }
}  

Commits the database transaction.

The Commit method is equivalent to the MySQL SQL statement COMMIT.

Examples

The following example creates MySqlConnection and a MySqlTransaction. It also demonstrates how to use the MySqlConnection.BeginTransaction, Commit, and Rollback methods.

Visual Basic example:

Public Sub RunSqlTransaction(myConnString As String)
    Dim myConnection As New MySqlConnection(myConnString)
    myConnection.Open()
    
    Dim myCommand As MySqlCommand = myConnection.CreateCommand()
    Dim myTrans As MySqlTransaction
    
    ' Start a local transaction
    myTrans = myConnection.BeginTransaction()
    
    ' Must assign both transaction object and connection
    ' to Command object for a pending local transaction
    myCommand.Connection = myConnection
    myCommand.Transaction = myTrans
    
    Try
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (100, 'Description')"
      myCommand.ExecuteNonQuery()
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (101, 'Description')"
      myCommand.ExecuteNonQuery()
      myTrans.Commit()
      Console.WriteLine("Success.")
    Catch e As Exception
      Try
        myTrans.Rollback()
      Catch ex As MySqlException
        If Not myTrans.Connection Is Nothing Then
          Console.WriteLine("An exception of type " & ex.GetType().ToString() & _
                            " was encountered while attempting to roll back the transaction.")
        End If
      End Try
    
      Console.WriteLine("An exception of type " & e.GetType().ToString() & _
                      "was encountered while inserting the data.")
      Console.WriteLine("Neither record was written to database.")
    Finally
      myConnection.Close()
    End Try
End Sub

C# example:

public void RunSqlTransaction(string myConnString) 
 {
    MySqlConnection myConnection = new MySqlConnection(myConnString);
    myConnection.Open();
    MySqlCommand myCommand = myConnection.CreateCommand();
    MySqlTransaction myTrans;
    // Start a local transaction
    myTrans = myConnection.BeginTransaction();
    // Must assign both transaction object and connection
    // to Command object for a pending local transaction
    myCommand.Connection = myConnection;
    myCommand.Transaction = myTrans;
    try
    {
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (100, 'Description')";
      myCommand.ExecuteNonQuery();
      myCommand.CommandText = "Insert into mytable (id, desc) VALUES (101, 'Description')";
      myCommand.ExecuteNonQuery();
      myTrans.Commit();
      Console.WriteLine("Both records are written to database.");
    }
    catch(Exception e)
    {
      try
      {
        myTrans.Rollback();
      }
      catch (MySqlException ex)
      {
        if (myTrans.Connection != null)
        {
          Console.WriteLine("An exception of type " + ex.GetType() +
                            " was encountered while attempting to roll back the transaction.");
        }
      }
    
      Console.WriteLine("An exception of type " + e.GetType() +
                        " was encountered while inserting the data.");
      Console.WriteLine("Neither record was written to database.");
    }
    finally 
    {
      myConnection.Close();
    }
}