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Devart.Data.PostgreSql Namespace / PgSqlTransaction Class / Rollback Method / Rollback() Method
Example

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    Rollback() Method
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    Rolls back a database transaction from a pending state.
    Syntax
    '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 PgSqlConnection.BeginTransaction has been called, but before Commit is called).
    Example
    The following example creates a PgSqlConnection and a PgSqlTransaction. It also demonstrates how to use the PgSqlConnection.BeginTransaction, Commit, and Rollback methods.
    public void RunPgSqlTransaction(string myConnString)
    {
      PgSqlConnection pgConnection = new PgSqlConnection(myConnString);
      pgConnection.Open();
    
      PgSqlCommand pgCommand = new PgSqlCommand();
      PgSqlTransaction myTrans;
    
      // Start a local transaction
      myTrans = pgConnection.BeginTransaction();
      // Assign transaction object for a pending local transaction
      pgCommand.Transaction = myTrans;
    
      try
      {
        pgCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(50, 'DEVELOPMENT')";
        pgCommand.ExecuteNonQuery();
        pgCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(60, 'PRODUCTION')";
        pgCommand.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
      {
        pgConnection.Close();
      }
    }
    Public Sub RunPgSqlTransaction(myConnString As String)
      Dim pgConnection As New PgSqlConnection(myConnString)
      pgConnection.Open()
    
      Dim pgCommand As New PgSqlCommand()
      Dim myTrans As PgSqlTransaction
    
      ' Start a local transaction
      myTrans = pgConnection.BeginTransaction()
      ' Assign transaction object for a pending local transaction
      pgCommand.Transaction = myTrans
    
      Try
        pgCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(50, 'DEVELOPMENT')"
        pgCommand.ExecuteNonQuery()
        pgCommand.CommandText = "INSERT INTO Test.Dept(DeptNo, DName) Values(60, 'PRODUCTION')"
        pgCommand.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
        pgConnection.Close()
      End Try
    End Sub
    Requirements

    Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

    See Also