MySQL - 执行“SELECT table1.,table2.column FROM table1,table2"是否合法? [英] MySQL - is it legal to do 'SELECT table1.,table2.column FROM table1,table2'?

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MySQL - 执行 'SELECT table1.*,table2.column FROM table1,table2' 是否合法?

MySQL - is it legal to do 'SELECT table1.*,table2.column FROM table1,table2'?

是合法的，但是会给你两个表的笛卡尔积.您确定要笛卡尔积吗?

It is legal, but it will give you a Cartesian product of the two tables. Are you sure that you want a Cartesian Product?

大多数情况下，您会使用 JOIN，如下所示:

Most times, you would use a JOIN as in:

Select Table1.*, Table2,ColumnName
From Table1
    INNER JOIN Table2
        ON Table1.PKColumn = Table2.FKColumn

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MySQL - 执行“SELECT table1.*,table2.column FROM table1,table2"是否合法? [英] MySQL - is it legal to do &#39;SELECT table1.*,table2.column FROM table1,table2&#39;?