从 JSON 数组连接列表

Question

假设我在项目数据库中有 json：

第 1 行：

{"Id": "1", "Items": [{"Item": "Test Item", "Price": ".00"}, {"Item": "Test Item #2", "Price": ".00"}]}

第 2 行：

{"Id": "2", "Items": [{"Item": "Test Item #3", "Price": ".00"}, {"Item": "Test Item #1", "Price": ".00"}]}

我如何获得像这样格式化的行（| 是列分隔符）：

1 | Test Item, Test Item #2
2 | Test Item #3, Test Item #1

Answer 1

SELECT  ID || '|' || ARRAY_TO_STRING( ARRAY_AGG( ITEMS ), ', ')
FROM
    (
        SELECT T.J->>'Id' AS ID, json_array_elements((T.J->'Items')::json)->>'Item' AS ITEMS
        FROM
        (
            SELECT ('{"Id": "1", "Items": [{"Item": "Test Item", "Price": ".00"}, {"Item": "Test Item #2", "Price": ".00"}]}')::json AS J
            UNION all
            SELECT ('{"Id": "2", "Items": [{"Item": "Test Item #3", "Price": ".00"}, {"Item": "Test Item #1", "Price": ".00"}]}')::json AS J
        ) T
    ) T
GROUP   BY ID

从 JSON 数组连接列表

Concatenate list from JSON array

postgresql

postgresql-json