Question

我有两张桌子。

表A

 id |       json       
----+------------------
  a | {"st":[{"State": "TX", "Value":"0.02"}, {"State": "CA", "Value":"0.2" ...
----+------------------
 b  | {"st":[{"State": "TX", "Value":"0.32"}, {"State": "CA", "Value":"0.47" ...

表B

idx |  state| dir     
----+-------+----------
  1 | TX    | 123
----+-------+----------
  2 | CA    | 15

我想使用表B中的列temp来过滤表A.而表B将根据idx值选择。

当状态等于从tableB创建的临时表时，我想从每一行中选择值，其中idx是确定的数字

让我们说idx等于2.这意味着我可以使用以下sql查询创建临时表

with tempT AS(
SELECT * 
FROM tableB 
where idx = 2);

这就是我想要实现的目标

idx |  state| value     
----+-------+----------
  2 | CA    | 0.2
----+-------+----------
  2 | CA    | 0.47

我该怎么做？

Answer 1

您应该使用jsonb_array_elements之类的：

WITH A AS
  (SELECT 'a' AS id,
          '{"st":[{"State": "TX", "Value":"0.02"}, {"State": "CA", "Value":"0.2"}]}'::jsonb AS json
   UNION SELECT 'b' AS id,
                '{"st":[{"State": "TX", "Value":"0.32"}, {"State": "CA", "Value":"0.47"}]}'::jsonb AS json),
     B AS
  (SELECT 1 AS idx,
          'TX' AS state,
          123 AS dir
   UNION SELECT 2 AS idx,
                'CA' AS state,
                15 AS dir)
SELECT *
FROM
  (SELECT A.id,
          jsonb_array_elements(A.json->'st') AS obj
   FROM A) AS A
inner JOIN B on  B.state = obj->>'State'::text
where B.idx = 2;

如何将值从另一个表传递到postgres中的jsonb

1 个答案: