本文实例讲述了MySQL中USING 和 HAVING 用法。分享给大家供大家参考,具体如下:
USING
用于表连接时给定连接条件(可以理解为简写形式),如
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SELECT * FROM table1 JOIN table2 ON table1.id = table2.id |
使用 USING 可以写为
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SELECT * FROM table1 JOIN table2 USING(id) |
HAVING
引入 HAVING 是因为 WHERE 无法和统计函数一起使用
如表 order (定单)有如下字段:
id, date, price, customer
查找订单总额少于2000的客户可以这样写:
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SELECT customer, SUM (price) FROM order GROUP BY customer HAVING SUM (price)<2000 |
查找指定客户中订单超过1500的订单总额:
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SELECT customer, SUM (price) FROM order WHERE customer= '…' OR customer = '…' GROUP BY customer HAVING SUM (price) > 1500 |
希望本文所述对大家MySQL数据库计有所帮助。
原文链接:https://blog.csdn.net/qq_42176520/article/details/89852547