Question

我在jsonb类型的列中存储了以下JSON。我想查询外部数组的第二个元素，并将“cid”列中具有值的所有行过滤为“CID1”。

{"root":[[
            {"cid":"CID1","Display":"User One","FName":"User","LName":"One"},
            {"cid":"CID1","Display":"User Two","FName":"User","LName":"Two"},
            {"cid":"CID1","Display":"User Three","FName":"User","LName":"Three"},
            {"cid":"CID2","Display":"User One","FName":"User","LName":"One"},
            {"cid":"CID2","Display":"User Two","FName":"User","LName":"Two"},
            {"cid":"CID2","Display":"User Three","FName":"User","LName":"Three"}    

            ],
            [
            {"cid":"CID1","Display":"User One","FName":"Userfff","LName":"One"},
            {"cid":"CID1","Display":"User Two","FName":"User","LName":"Two"},
            {"cid":"CID1","Display":"User Three","FName":"User","LName":"Three"},
            {"cid":"CID2","Display":"User One","FName":"User","LName":"One"},
            {"cid":"CID2","Display":"User Two","FName":"User","LName":"Two"},
            {"cid":"CID2","Display":"User Three","FName":"User","LName":"Three"}    
            ]]}

我编写了以下查询，并成功地从第二个数组中检索了所有行作为JSON对象，但是当我尝试过滤它们时，我得到了错误

42703：列“filterin”不存在

select jsonb_array_elements((ARRAY(select jsonb_array_elements(msg->'root') ele ))[2]::jsonb) filterin 
from js
where filterin->>'cid'='CID1';

我应该在以下查询中更正哪些内容，以便我能够对列进行过滤？

Answer 1

输出别名不能在WHERE部分中使用。您有两种选择：子查询或复制定义。

select jsonb_array_elements((ARRAY(select jsonb_array_elements(msg->'root') ele ))[2]::jsonb) filterin
from js
where jsonb_array_elements((ARRAY(select jsonb_array_elements(msg->'root') ele ))[2]::jsonb)->>'cid'='CID1';

或

SELECT filterin FROM 
(select jsonb_array_elements((ARRAY(select jsonb_array_elements(msg->'root') ele ))[2]::jsonb) filterin
from js) data
WHERE filterin->>'cid'='CID1';

过滤PostgreSQL JSONB列不起作用

1 个答案: