当某些记录不符合FK约束时，如何将记录从一个表插入到另一个表？

Question

I have a source table that has 10,000 records that I want to insert into a destination table. The insert would also include an ID field. There is a third table with a foreign key relationship on the id field. How do I insert the records that have the correct ids for the FK and skip the ones that don't have the correct ids for the FK?

Set IDENTITY_INSERT Destination ON
GO

INSERT INTO [dbo].[Destination]
           (
           Id,
           [Street1]
           ,[Street2]
           ,[City]
           ,[State]
           ,[PostalCode]
           ,[ContactId]
           ,[Institution_ID]
           ,[LegacyIDNumber]
           )
 SELECT DISTINCT
 [Account Number],
    [Address],
    [Address 2],
    [City],
    Left([State],2),
    [Postal Code],
    [Account Number],
    [Account Number],
    [Account Number]
FROM  [dbo].[Source]
GO

Set IDENTITY_INSERT Destination OFF
GO

The error I get is

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Destination_dbo.Contacts_ContactId". The conflict occurred in database "xxxx", table "dbo.Contacts", column 'Id'.
The statement has been terminated.

Answer 1

You could add an INNER JOIN to the Contacts table to ensure that the [Account Number] from the source matches the Id in the Contacts table. Anything that doesn't match would get filtered out which should keep you from getting the error about the FK constraint.

SELECT [Account Number],
    [Address],
    [Address 2],
    [City],
    Left([State],2),
    [Postal Code],
    [Account Number],
    [Account Number],
    [Account Number]
FROM  [dbo].[Source]
INNER JOIN dbo.Contacts ON Contacts.id=Source.[Account Number]

There is probably a query hint or some other database trick that would allow you to pull this off more properly. But AFAIK the above should work.