The INSERT statement conflicted with the FOREIGN KEY constraint

Error: System.Data.SqlClient.SqlException: The INSERT st开发者_StackOverflow中文版atement conflicted with the FOREIGN KEY constraint "FK__Item__order__3AE27131". The conflict occurred in database "pmall", table "dbo.ItemSaved", column 'id'.

Here's my table:

ItemSavedUnits

• id
• ItemID (is set in this table a FK to Item.id)
• ...etc.

Here's my insert statement:

insert into ItemSavedUnits (ItemID, name, Price)
select ItemID, name,Price
from ItemUnits where ItemID = 92439 

I don't really understand why if I a FK constraint on ItemSavedUnits.ItemID that is related to Item.ItemID and ItemUnits has no constraints at all why I'm getting a problem inserting into ItemSavedUnits. The ItemID I'm tryign to insert does exist in the Item table.

Are you absolutely sure that ItemId 92439 exists in the Item table, and not just in ItemUnits?

or

Is your select statement returning null?

It looks like you need a row in ItemUnits with that ID first - what does the SELECT statement part of your insert return? No rows?

Also, is there a trigger on the ItemSavedUnits table that could be causing problems?

Your foreign key constraint violation doesn't appear to deal with the ItemSavedUnits table - the violation exception is being thrown by the constraint on the ItemSaved table, not the ItemSavedUnits table. Is there a trigger on ItemSavedUnits that's trying to insert into ItemSaved?