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?