mysql - 我如何在 MySQL 中执行此查询(来自不同表的多个列)

Question

我想从不同的表中选择 3 列，但我必须使用函数，这是我想要执行的查询:

SELECT DISTINCT table1.sum(column1) as sumcol1,
      table2.sum(column2) as sumcol2, table3.column3 as col3 
 FROM db1.table1, db1.table2, db1.table3 
WHERE table1.id = 1  AND table2.id = 1 AND table3.id = 1;

注意:只有table3.id是唯一索引
我想得到这张表:

 |sumcol1|sumcol2|col3|
 |1234556|5432113|432|

Answer 1

既然你没有提到逻辑。看起来像是放错位置的 SUM

SELECT DISTINCT sum(table1.column1) as sumcol1,
          sum(table2.column2) as sumcol2, table3.column3 as col3 
     FROM db1.table1, db1.table2, db1.table3 
    WHERE table1.id = 1  AND table2.id = 1 AND table3.id = 1;