postgresql子查询有问题

时间:2014-01-15 22:01:45

标签: sql database postgresql subquery

以下是我的表格:

表1:

ID | data1 | data2
1  | xxx   | xxx 
2  | xxx   | xxx

表2:

ID | table1_id
20 | 1
21 | 1
25 | 2
26 | 2

表3:

ID | table2_id
30 | 20
31 | 21
32 | 25
33 | 26 <--

我已用箭头标记相关行(表3:ID = 33 | table2_id = 26

现在,我希望匹配ID与表1中的数据1和数据2.在这种情况下: 2

我试了一下......

SELECT t1."ID"
FROM table AS t1

INNER JOIN table2 AS tb2
ON t1."ID" = t2."ID"

INNER JOIN table3 AS t3
ON t2."ID" = 26

......但它什么都没有。有人给我一个工作子查询:)

1 个答案:

答案 0 :(得分:1)

你加入了错误的领域

SELECT t1."ID"
FROM table AS t1

INNER JOIN table2 AS t2
   ON t1."ID" = t2.table1_id

INNER JOIN table3 AS t3
   ON t2."ID" = t3.table2_id
WHERE t3."ID" = 33