问异常调用"ExecuteNonQuery“

EN

$SQL_insert = "BEGIN
              IF NOT EXISTS (SELECT 1
                             FROM [dbo].[Group_Stats]
                             WHERE Date_of_Record = CAST(GETDATE() AS DATE)
                             AND [Group] = '$group')
              BEGIN
                  INSERT INTO [dbo].[Group_Stats] ([Date_of_Record], [Group], [Windows_SEP_11],[Mac_SEP_11],[Windows_SEP_12],[Mac_SEP_12])
                  VALUES (CAST(GETDATE() AS DATE), REPLACE ('$group', 'My Company\', ''), $win_sep_11, $mac_sep_11, $win_sep_12, $mac_sep_12)
              END
          END"

Exception calling "ExecuteNonQuery" with "0" argument(s): "Violation of PRIMARY KEY constraint 'PK_Group_Stats'. Cannot insert duplicate key in object 'dbo.Group_Stats'.