System.Data.ConstraintException: Failed to enable constraint

Question

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.ConstraintException: Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.

Source Error:

Line 2960:            this.Adapter.SelectCommand = this.CommandCollection[5]; Line 2961:            CDS.ADDJOB_SELECTDataTable dataTable = new CDS.ADDJOB_SELECTDataTable(); Line 2962:            this.Adapter.Fill(dataTable); Line 2963:            return dataTable; Line 2964:        }