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有一个schema如下
fish（name,species,tankid） eat(species1，species2)
其中eat表示鱼类之间相互捕食关系，species1是被捕食的鱼类tankid表示鱼缸id
需要筛选出：与可以捕食他的鱼（species2）放在同一个鱼缸中（tankid相等）的鱼（species1）的名字
求用sql语句说明
好好学习，天天向上！！！
Mysql filters the same values in a column of data under restricted conditions? -PHP Chinese website Q&A-Mysql filters the same values in a column of data under restricted conditions? -PHP Chinese website Q&A
Let’s take a look and learn.
SELECT a.*, b.name AS name1, c.name AS name2 FROM eat AS a LEFT JOIN fish AS b ON a.species1=b.species LEFT JOIN fish AS c ON a.species2=c.species WHERE b.tankid=c.tankid
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Mysql filters the same values in a column of data under restricted conditions? -PHP Chinese website Q&A-Mysql filters the same values in a column of data under restricted conditions? -PHP Chinese website Q&A
Let’s take a look and learn.