Question

我有json类型字段，类似这样

数据

{"age": 44, "name": "Jun"}

{"age": 19, "name": "Pablo", "attempts": [11, 33, 20]}

{"age": 33, "name": "Maria", "attempts": [77, 10]}

这里有一些json数据有＆＃34;尝试＆＃34;数组，有些不是。当json有这个数组时，我需要在不同的字段中得到数组元素的总和，需要像

这样的结果

数据，sum_of_array

{"age": 44, "name": "Jun"} , (nothing here)

{"age": 19, "name": "Pablo", "attempts": [11, 33, 20]} , 64

{"age": 33, "name": "Maria", "attempts": [77, 10]} , 87

Answer 1

SELECT attempts.id,
       sum(vals.v::integer) sum_attempts
FROM attempts
   LEFT JOIN LATERAL jsonb_array_elements_text(val->'attempts') vals(v)
      ON TRUE
GROUP BY attempts.id;

如果您使用json_array_elements_text而不是json，请使用jsonb。

Answer 2

如果您的表格中有唯一的id标识列

，则此方法有效

SELECT your_table.*, tt.sum FROM your_table
LEFT JOIN (
    select id, SUM(arrvals) as sum FROM (
        select id, json_array_elements_text(CAST(your_json_column->>'attempts' AS json))::NUMERIC as arrvals  from your_table
    )t 
     group by id
) tt
ON your_table.id = tt.id

json数组的总和

2 个答案: