记录一下中多表查询。
表1:品牌:brands( brandid vARCHAR(20),
brand VARCHAR(20),
remark vARCHAR(100))
表2:类型:types( typeid vARCHAR(20),
type VARCHAR(20),
remark vARCHAR(100))
表3:品牌:levels( levelid vARCHAR(20),
level VARCHAR(20),
remark vARCHAR(100))
表4:油品:oils( oilid vARCHAR(20),brandid VARCHAR(20),typeid vARCHAR(20),levelid vARCHAR(20),remark vARCHAR(100))
说明一下:前三个表为基本信息,即油品的品牌、类型、级别,表4为油品信息,那么该如何显示油品的基本信息呢?
select brands.brand,types.type,levels.level from oils
inner join brands on oils.brandid = brands.brandid
inner join types on oils.typeid =types.typeid
inner join levels on oils.levelid =levels.levelid