Mastering GUI Programming with Python

SQL subqueries

A SELECT statement can be embedded in another SQL statement by putting it in parentheses. This is called a subquery. Exactly where it can be embedded depends on what kind of data the query is expected to return:

• If the statement will return a single row and column, it can be embedded wherever a single value is expected
• If the statement will return a single column with multiple rows, it can be embedded wherever a list of values is expected

• If the statement will return multiple rows and columns, it can be embedded wherever a table of values is expected

Consider this query:

SELECT coffees.coffee_brand, coffees.coffee_nameFROM coffees    JOIN (    SELECT * FROM roasts WHERE id > ( SELECT id FROM roasts WHERE description = 'Medium' ...