I am trying to update all of one field's table to another field's data based upon a link between the two tables.:
UPDATE CustSalesByPartPastYearTemp SET CustItem = (SELECT [CUST ITEM #] FROM [INVOICE DETAILS] INNER JOIN CustSalesByPartPastYearTemp ON [INVOICE DETAILS].[LINESERIAL#] = CustSalesByPartPastYearTemp.LineSerial)
Basically, I want the field CustItem in table CustSalesByPartPastYearTemp to equal what the field CUST ITEM # in the table INVOICE DETAILS is by linking the fields LineSerial and LINESERIAL#.
This gives an error saying :Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
I am attempting to run this on an .asp page, sql-2000 is the back end database.