Mysql之查询基础select

查询基础select

列的查询：select +lname from +tablename;

Select shohin_id,shohin_mei,shiire_tanka from shohin;

为列定义别名AS

Select shohin_id AS id,

shohin_mei AS namae,

shoiire_tanka AS tanka from shohin;

Select shohin_id as “商品编号”,shohin_mei as “商品名称”,shohin_tanka as “进货单价” from shohin;

常数的查询

Select ‘商品’ as mojiretsu,38 as kazu,’2009-02-24’ as hizuke,shohin_id,shohin_mei from shohin;

Select distinct shohin_bunrui from shohin;//去除重复的项目

Select distinct shiire_tanka from shohin;

Select +liename from tablename where <表达式>;

Select shohin_mei,shohin_bunrui from shohin where shohin_bunrui = ‘衣服’;

Select distinct shohin_id,shiire_tanka from shohin;

Select shohin_mei,hanbai_tanka,hanbai_tanka * 2 as “hanbai_taka_x2” from shohin;