MySQL____将查询结果插入到表中

insert与select的嵌套使用的方法

下面select的数据封装成了视图？然后将其数据插入到exchangeinfo表中

INSERT INTO wc_exchangeinfo(exchangeid2,exchangeid) SELECT * FROM (SELECT wc_exchange.id,wc_exchangeinfo.exchangeid FROM wc_exchange LEFT JOIN wc_exchangeinfo ON wc_exchange.id=wc_exchangeinfo.exchangeid)AS a

试验后发现直接将查询结果插入也可以

INSERT INTO wc_exchangeinfo(exchangeid2,exchangeid) SELECT wc_exchange.id,wc_exchangeinfo.exchangeid FROM wc_exchange LEFT JOIN wc_exchangeinfo ON wc_exchange.id=wc_exchangeinfo.exchangeid

试验后发现，每一个派生出的新表都必须指定别名才可以。否则报错：Every derived table must have its own alias