<docs> <Class> <summary> Represents a SQL transaction to be made in a MySQL database. This class cannot be inherited. </summary> <remarks> The application creates a <B>MySqlTransaction</B> object by calling <see cref="MySqlConnection.BeginTransaction()"/> on the <see cref="MySqlConnection"/> object. All subsequent operations associated with the transaction (for example, committing or aborting the transaction), are performed on the <B>MySqlTransaction</B> object. </remarks> <example> The following example creates a <see cref="MySqlConnection"/> and a <B>MySqlTransaction</B>. It also demonstrates how to use the <see cref="MySqlConnection.BeginTransaction()"/>, <see cref="MySqlTransaction.Commit"/>, and <see cref="MySqlTransaction.Rollback"/> methods. <code lang="vbnet"> Public Sub RunTransaction(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 Region (RegionID, RegionDescription) VALUES (100, 'Description')" myCommand.ExecuteNonQuery() myCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')" myCommand.ExecuteNonQuery() myTrans.Commit() Console.WriteLine("Both records are written to database.") 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 'RunTransaction </code> <code lang="C#"> public void RunTransaction(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 Region (RegionID, RegionDescription) VALUES (100, 'Description')"; myCommand.ExecuteNonQuery(); myCommand.CommandText = "Insert into Region (RegionID, RegionDescription) 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(); } } </code> </example> </Class> <Rollback> <summary> Rolls back a transaction from a pending state. </summary> <remarks> 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). </remarks> <example> The following example creates a <see cref="MySqlConnection"/> and a <see cref="MySqlTransaction"/>. It also demonstrates how to use the <see cref="MySqlConnection.BeginTransaction()"/>, <see cref="Commit"/>, and <B>Rollback</B> methods. <code lang="vbnet"> 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 </code> <code lang="C#"> 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(); } } </code> </example> </Rollback> <Commit> <summary> Commits the database transaction. </summary> <remarks> The <b>Commit</b> method is equivalent to the MySQL SQL statement COMMIT. </remarks> <example> The following example creates a <see cref="MySqlConnection"/> and a <see cref="MySqlTransaction"/>. It also demonstrates how to use the <see cref="MySqlConnection.BeginTransaction()"/>, <see cref="Commit"/>, and <B>Rollback</B> methods. <code lang="vbnet"> 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 </code> <code lang="C#"> 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(); } } </code> </example> </Commit> </docs>