09 2023 档案

摘要:SELECT COUNT(*) FROM ( SELECT * FROM table1 UNION SELECT * FROM table2 ) AS combined GROUP BY column1, column2, ...;我们首先将两个表的数据内容进行UNION操作,然后使用GROUP B 阅读全文
posted @ 2023-09-17 15:57 妖狐鬼魅 阅读(410) 评论(0) 推荐(0) 编辑

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