9、进阶查询 - 2、having - 《Mysql》

having跟where一样, 用来做条件的判断和数据的筛选过滤

在MySQL中，我们可以使用where进行条件的过滤, 也可以使用having.

示例

# 可以用where也可以用having
SELECT * FROM `t1` WHERE `age` > 18;
SELECT * FROM `t1` HAVING `age` > 18;

演示

where和having的区别

示例

查询差价>200的商品信息

# 使用where
SELECT `goods_name`,  market_price-shop_price as `chajia`
FROM `goods`
WHERE market_price-shop_price > 200;

# 使用having
SELECT `goods_name`,  market_price-shop_price as `chajia`
FROM `goods`
HAVING chajia > 200;

group和having综合示例

查询该店每个栏目下面积压的总货款

SELECT `cate_id`, sum(goods_number*shop_price) as `jiya`
FROM `goods`
GROUP BY `cate_id`;

查询积压货款>1000的栏目

SELECT `cate_id`, sum(goods_number*shop_price) as `jiya`
FROM `goods`
GROUP BY `cate_id`
HAVING `jiya`>1000;

结论