MYSQL中把查询结果导入新表 以及 多表连接查询去掉重复列

 

一、 SELECT * INTO T1 FROM T2 这种语法在mysql中会报错,用下面的语法代替即可

 A> 当新表不存在,需要新建时:

CREATE TABLE rice_test
(SELECT 商品名称, 商品链接 FROM rice_june
WHERE `平台` = '苏宁');

A> 当新表已经存在,且需要全字段插入时(新表与源表的字段要完全一致):

INSERT INTO `beer-new-june`
SELECT * from `beer-missed`;

 A> 当新表已经存在,只需要插入指定的某几列的数据时:

INSERT INTO `beer-new-june` (field1, field2, field3,...,field9)
SELECT  field1, field2, field3,...,field9  from `beer-missed`;

 

二、 mysql多表连接查询时,要去掉重复列,可以用USING()效果等同ON T1.ID = T2.ID


SELECT *
FROM total AS t1 LEFT JOIN (
SELECT DISTINCT 商品链接, 商品主图片链接 AS 商品主图
FROM rice_june) AS t2 USING(商品链接);

 

三个表连接的时候如下:

select * from (select * from school left join course USING (courseid)) e left join student USING (studentid);

参考:(5条消息) mysql多表连接查询(去掉重复列)_hc1428090104的博客-CSDN博客_sql表连接去掉重复结果列

posted @ 2021-07-15 17:58  sauron2021  阅读(1380)  评论(0编辑  收藏  举报