25在SQLServer2000中,有商品表商品号,商品号,单价和销售表商品号,销售时间,销售价格。现要限制“销售价格”的取值必须在此商品“单价”的0.6到1.5倍范围之内,实现这个约束的正确代码是
(A)CHECK(销售价格BETWEEN单价*0.6AND单价*1.5
(B)CHECK销售价格BETWEEN商品表.单价*0.6AND商品表.单价*1.5
(C)CREATETRIGGERtri_SalesON销售表FORINSERT,UPDATE
AS
IFEXISTSSELECT*FROMINSERTEDaJOIN商品表b
ONa.商品号=b.商品号
WHERE销售价格NOTBERWEEN单价*0.6AND单价*1.5
ROLLBACK
(D)CEATETRIGGERtri_SalesON销售表INSTEADOFINSERT,UPDATE
AS
IFEXISTSSELECT*FROMINSERTEDaJOIN商品表b
ONa.商品号=b.商品号
WHERE销售价格NOTBERWEEN单价*0.6AND单价*1.5
ROLLBACK