A.select * from wg B.show tbales C.show databases D.show * from wg
A.select ID from wg B.show ID from wg C.select * from student group by ID D.show * from wg
A.select * from ds.phones where Brand="華為"and model="P20" B.select * from ds.phones where Brand="華為"or model="P20" C.select * from ds.phones where having"華為"and"P20" D.select * from ds.phones where having"華為"or"P20"