连接查询
摘要:union 同时查询多个表,去除重复部分 eg: select 1 one,2 twounion SELECT 2 one,2 englich; left join 左外连接查询 eg: select * from table1 left join table2 on table1.id = tab
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posted @ 2022-08-23 21:51
posted @ 2022-08-23 21:51
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