组合where子句
and操作符
SELECT * FROM products WHERE vend_id = 'DLL01' AND prod_price <= 4;
OR操作符
SELECT * FROM products WHERE vend_id = 'DLL01' OR vend_id = 'BRS01';
求值顺序
SELECT * FROM products WHERE (vend_id = 'DLL01' OR vend_id = 'BRS01') AND prod_price >= 10;
SELECT * FROM products WHERE vend_id = 'DLL01' OR vend_id = 'BRS01' AND prod_price >= 10;
IN操作符
SELECT * FROM products WHERE vend_id IN ('DLL01', 'BRS01') ORDER BY prod_name;
NOT操作符
SELECT * FROM products WHERE NOT vend_id = 'DLL01';