A.將表達(dá)式分組 B.改變求值的次序 C.增加表達(dá)式的可讀性 D.沒有作用
A.Select* From Student Where Age>=20 ANDAge>=30 B.Select* From Student Where Age>=20 ANDAge<=30 C.Select* From Student Where Age BET WENN 20AND30 D.Select* From Student Where Age>=20&&Age>=30"
A、BETWEEN……AND…… B、>= C、AND D、NOT