Issue with query in a form

[andy1970]

I am getting an error when trying to save that says index or primary key cannot contain a null value. I have a query built from the query builder. The first one works the second does not. The only difference is the second has a field from the tbl_Computer_Attributes table in the select. This is from Access 2007. There must be a limitation on the number of JOINS or how it updates the tables. Here is the SQL and the query schema:
SELECT tbl_Hardware_Device.Device_ID, tbl_Hardware_Device.Product_ID, tblkp_Hardware_Info.Type, tbl_Device_Attributes.OE_Number


FROM tblkp_Hardware_Info INNER JOIN (tbl_Harware_Product INNER JOIN ((tbl_Hardware_Device LEFT JOIN tbl_Computer_Attributes ON tbl_Hardware_Device.Device_ID = tbl_Computer_Attributes.Device_ID) LEFT JOIN tbl_Device_Attributes ON tbl_Hardware_Device.Device_ID = tbl_Device_Attributes.Device_ID) ON tbl_Harware_Product.Product_ID = tbl_Hardware_Device.Product_ID) ON tblkp_Hardware_Info.Hardware_Info_ID = tbl_Harware_Product.Hardware_Info_ID;

SELECT tbl_Hardware_Device.Device_ID, tbl_Hardware_Device.Product_ID, tblkp_Hardware_Info.Type, tbl_Device_Attributes.OE_Number, tbl_Computer_Attributes.BIOAS
FROM tblkp_Hardware_Info INNER JOIN (tbl_Harware_Product INNER JOIN ((tbl_Hardware_Device LEFT JOIN tbl_Computer_Attributes ON tbl_Hardware_Device.Device_ID = tbl_Computer_Attributes.Device_ID) LEFT JOIN tbl_Device_Attributes ON tbl_Hardware_Device.Device_ID = tbl_Device_Attributes.Device_ID) ON tbl_Harware_Product.Product_ID = tbl_Hardware_Device.Product_ID) ON tblkp_Hardware_Info.Hardware_Info_ID = tbl_Harware_Product.Hardware_Info_ID;

[andy1970]

I figured it out. The attribute tables cannot have the Device_ID as the primary key in the one to one relationship. Access pretty much forces you to have an autonumber as a primary key for each table.

[tanvi]

This error occurs when you executed a query that tried to put a Null value in a primary key field. To solve this issue, you must enter a value in the primary key field before moving to another record.