This repository contains a demonstration of an uncommon SQL error: a subquery returning more than one row when only one is expected. The bug.sql file shows the problematic query, and bugSolution.sql ...

Subqueries can be used to return either a scalar (single) value or a row set; whereas, joins are used to return rows. A common use for a subquery may be to calculate a summary value for use in a query ...

The bug.sql file contains the erroneous SQL code. The bugSolution.sql file provides the corrected code, showing how to properly handle situations where a subquery might return multiple rows.

I'm having a bit of a problem with some SQL. I'm trying to do a match from one table to another. It works perfectly except for the last line. As soon as I add it NOTHING gets updated. I'm using ...