Hi Bob,

unfortunately no NULLs are being returned. I'm wondering if the problem is due to multiple rows being returned. Would I need to return it to an EntityList rather than an Entity? (LATER: I changed the code to return an entitylist but the same error occurs.) My Code is this:

In the class definition:

protected Receipt oReceipt;

Where the error occurs:

                mmSaveDataResult result = this.Save(this.oReceipt, this.dsReceipt, this.oReceipt.TableName);
                if (result == mmSaveDataResult.RulesPassed)
                {
                    LocalReport report = new LocalReport();
                    report.ReportPath = "ReceiptPrint.rdlc";
                    this.oReceipt.GetReceiptByPKForPrint(this.oReceipt.Entity.ReceiptPK);
                    DataSet dsReceipt = oReceipt.DataSet; // (DataSet)Session["dsReceipt"];
                    report.DataSources.Add(new ReportDataSource("ReceiptPrint_Receipt", dsReceipt.Tables[0]));

                    Reporting oPrint = new Reporting();

                    oPrint.Export(report);
                    oPrint.m_currentPageIndex = 0;
                    oPrint.Print();
...

>Frank,
>
>I have got this error a few times and every time it had to do with nulls being returned in the result set. I always fixed it by removing the null value in the column by using the ISNULL function and returning 0 if a number or a blank space if characters.
>
>HTH
>
>Bob
>>Hi,
>>
>>using MM.NET 3.6 and VS2008.
>>
>>I'm not sure if this is a Mere Mortals thing or more general. I'm getting this error:
>>
>>

Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints. 
>>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 44:         public ReceiptEntity GetReceiptByPKForPrint(Guid receiptPK)
>>Line 45:         {
>>Line 46:             return this.GetEntity("ReceiptsSelectByPKForPrint",
>>Line 47:                 this.CreateParameter("@ReceiptPK", receiptPK));
>>Line 48:

>>
>>This is called when I want to print a receipt that has just been added to the database. It works when there is only one detail line in the receipt but when there are two lines I get this error.
>>
>>Any ideas as to what could be wrong here?