Rollback() Method

In This Topic

Rolls back a database transaction from a pending state.

Syntax

Visual Basic
C#

'Declaration
 
Public Overloads Overrides Sub Rollback()

public override void Rollback()

Remarks

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

Example

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

csharp

public void RunMySqlTransaction(string myConnString)
{
  MySqlConnection myConnection = new MySqlConnection(myConnString);
  myConnection.Open();

  MySqlCommand myCommand = new MySqlCommand();
  MySqlTransaction myTrans;

  // Start a local transaction
  myTrans = myConnection.BeginTransaction();
  // Assign transaction object for a pending local transaction
  myCommand.Transaction = myTrans;

  try
  {
    myCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(50, 'DEVELOPMENT')";
    myCommand.ExecuteNonQuery();
    myCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(60, 'PRODUCTION')";
    myCommand.ExecuteNonQuery();
    myTrans.Commit();
    Console.WriteLine("Both records are written to database.");
  }
  catch(Exception e)
  {
    myTrans.Rollback();
    Console.WriteLine(e.ToString());
    Console.WriteLine("Neither record was written to database.");
  }
  finally
  {
    myConnection.Close();
  }
}

Visual Basic

Public Sub RunMySqlTransaction(myConnString As String)
  Dim myConnection As New MySqlConnection(myConnString)
  myConnection.Open()

  Dim myCommand As New MySqlCommand()
  Dim myTrans As MySqlTransaction

  ' Start a local transaction
  myTrans = myConnection.BeginTransaction()
  ' Assign transaction object for a pending local transaction
  myCommand.Transaction = myTrans

  Try
    myCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(50, 'DEVELOPMENT')"
    myCommand.ExecuteNonQuery()
    myCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(60, 'PRODUCTION')"
    myCommand.ExecuteNonQuery()
    myTrans.Commit()
    Console.WriteLine("Both records are written to database.")
  Catch e As Exception
    myTrans.Rollback()
    Console.WriteLine(e.ToString())
    Console.WriteLine("Neither record was written to database.")
  Finally
    myConnection.Close()
  End Try
End Sub

Reference

MySqlTransaction Class
MySqlTransaction Members
Overload List
BeginTransaction Method
Commit Method
Save Method

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