取從postgres的

Question

我有具有2列的PostgreSQL 9.5表（樂器）JSON陣列列INSTRUMENT_ID和user_maps如下所示的結果是：

我想獲取基於以下條件的所有儀器：

• 遍歷user_maps每個JSON對象
• 計數具有沿Y狀態JSON對象的數量，N或d
• 計數應大於2

注：user_maps是具有2個字段的狀態和用戶id鏈接到INSTRUMENT_ID 「I01」

樣品user_maps JSON對象的數組：

[ 
    { 
    "status": "Y", 
    "userId": "ZU201707120539150007" 
    }, 
    { 
    "status": "D", 
    "userId": "ZU201707120540510008" 
    }, 
    { 
    "status": "I", 
    "userId": "ZU201707120542540009" 
    }, 
    { 
    "status": "I", 
    "userId": "ZU201707011725050001" 
    }, 
    { 
    "status": "Y", 
    "userId": "ZU201707120552050013" 
    } 
] 

儀器ID「I01」應該是最終結果。

另外，掛INSTRUMENT_ID 「I02」 樣品user_maps：

[ 
    { 
    "status": "I", 
    "userId": "ZU201707120539150007" 
    }, 
    { 
    "status": "I", 
    "userId": "ZU201707120540510008" 
    }, 
    { 
    "status": "I", 
    "userId": "ZU201707120542540009" 
    }, 
    { 
    "status": "I", 
    "userId": "ZU201707011725050001" 
    }, 
    { 
    "status": "Y", 
    "userId": "ZU201707120552050013" 
    } 
] 

儀器ID 「I02」 不該來的最終結果怎麼一回事，因爲它只有在（Y，N，d），具有狀態的一個JSON。

Answer 1

如果我理解正確你的請求，那麼這就是你如何能做到這一點：

-- This is just test dataset as you provided 
WITH test(instrument_id, user_maps) AS (
      VALUES 
       ( 'I01'::text, 
        $$[ 
         { "status": "Y", "userId": "ZU201707120539150007" }, 
         { "status": "D", "userId": "ZU201707120540510008" }, 
         { "status": "I", "userId": "ZU201707120542540009" }, 
         { "status": "I", "userId": "ZU201707011725050001" }, 
         { "status": "Y", "userId": "ZU201707120552050013" } 
        ]$$::jsonb), 
       ( 'I02'::text, 
        $$[ 
         { "status": "I", "userId": "ZU201707120539150007" }, 
         { "status": "I", "userId": "ZU201707120540510008" }, 
         { "status": "I", "userId": "ZU201707120542540009" }, 
         { "status": "I", "userId": "ZU201707011725050001" }, 
         { "status": "Y", "userId": "ZU201707120552050013" } 
        ]$$::jsonb) 
     ) 
SELECT t.instrument_id, 
     count(u) 
FROM test t, 
     jsonb_array_elements(user_maps) u  -- does lateral join to get json array elements 
WHERE u -> 'status' ?| ARRAY['Y', 'N', 'D'] -- your search condition 
GROUP BY 1 
HAVING count(u) > 2;       -- the count condition you wanted 

-- This is the result of the query 
instrument_id | count 
---------------+------- 
I01   |  3 
(1 row)