关于LEFT JOIN 的主表和子表的问题?

Question

例如 A LEFT JOIN B 中A是主标还是字表

Answer 1

Questions about the main table and sub-tables of LEFT JOIN? - PHP Chinese website Q&A - Questions about the main table and sub-tables of LEFT JOIN? - PHP Chinese website Q&A

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Answer 2

A是左表，B相当于子表，查询时A表全部内容都显示，B表中只会显示和A表中有交集的部分，B表不一定会全部显示