问题 I have a table of names and addresses, which includes a postcode column. I want to strip the spaces from the postcodes and select any that match a particular pattern. I'm trying this (simplified a bit) in T-SQL on SQL Server 2005: SELECT Replace(Postcode, ' ', '') AS P FROM Contacts WHERE P LIKE 'NW101%' But I get the following error; Msg 207, Level 16, State 1, Line 3 Invalid column name 'P'. If I remove the WHERE clause I get a list of postcodes without spaces, which is what I want to