为什么我的子表单在MS Access 2007的INS​​ERT操作中不包含来自父表单的外键？

Question

The problem

When I insert a new record in a multiple item subform, it throws an error as it hasn't included the required foreign key from the parent form. The foreign key isn't allowed to be null, and it's trying to insert a null value.

A bit more information

This process worked fine previously, but I have since upgraded my backend from ACE to SQL Server 2005. It now throws this error:

Run-time error '3146':
ODBC--call failed.
[Microsoft][ODBC SQL Server Driver][SQL Server]Cannot insert the value NULL into
column 'EngagementLetterID_FK', table 'ClientDatabase.dbo.Services'; column does
not allow nulls. INSERT fails. (#515) [Microsoft][ODBC SQL Server Driver][SQL
Server]The statement has been terminated. (#3621)

As quick comment, the subform is for Service records, and the parent form is for EngagementLetter records. One EL has many Services.

I've checked the table set up, and it seems fine, but I would say the table is operating as it should - it shouldn't allow a null value. Neither do I think SQL Server should be responsible for identifying the correct FK - the frontend should do this. However, my front end was working fine before with the ACE backend. So I'm having trouble finding out what the culprit is, and I can't figure out how to do more advanced Access debugging (eg beforeUpdate, tell me what the SQL INSERT query will be).

I've checked some of my other parent-sub forms, and they are behaving fine.

Any ideas?

Answer 1

One other detail that I forgot to mention - I had done some dramatic front end rebuilding at the same time. With the subform, I had not correctly linked EngagementLetterID_FK with EngagementLetterID from the parent form. The result of this is that a new Service record has not had the EngagementLetterID_FK specified.

So now that I have corrected the link, it's working fine.