sql中join与left-join图解区别

t1表内容以下:3d t2表内容以下:blog 下面来简述join和left join/right join的区别:get inner joinit select * from t1 inner join t2 on t1.id = t2.id;class 公共部分的数据才会被查询出来;select left joinim select * from t1 left join t2 on t1.i
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