分離行成多行基於數量

Question

我在我的表中的行：

id m_id quantity 
1 1 1500 
2 1 -1000 
3 2 -3000 
4 2 2000 
5 3 400 
6 3 -1000 
7 4 500 
8 4 -500 
9 5 1500 

我想創建一個視圖，將返回此：

id m_id quantity 
    1 1 500 
    2 1 1000 
    3 1 -1000 
    4 2 -1000 
    5 2 -2000 
    6 2 2000 
    7 3 400 
    8 3 -400 
    9 3 -600 
    10 4 500 
    11 4 -500 
    12 5 1500 

查看將返回相等值正面/負面，並將其餘分隔在不同的行中。因此，如果對於給定的m_id，正數和負數不同，那麼兩行被分成三行。

Answer 1

我想你可以使用這樣的查詢：

WITH t1 AS (
    SELECT *, 
     LAG(quantity) OVER (PARTITION BY m_id ORDER BY id) as pq, -- Previous quantity based on id 
     LEAD(quantity) OVER (PARTITION BY m_id ORDER BY id) as nq -- Next quantity based on id 
    FROM yourTable  
), t2 AS (
SELECT id, m_id, 1 as ord, 
    CASE 
     -- If sign is changed and quantity is bigger than that use next quantity 
     WHEN (SIGN(nq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(nq)) THEN -nq 
     -- If sign is changed and quantity is bigger than that use previous quantity 
     WHEN (SIGN(pq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(pq)) THEN -pq 
     -- Else use original quantity 
     ELSE quantity 
    END As quantity 
FROM t1 
UNION ALL -- Add extra rows 
SELECT id , m_id, 
    CASE 
     -- Set order to be higher than original quantity 
     WHEN (SIGN(nq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(nq)) THEN 0 
     -- Set order to be lower than original quantity 
     WHEN (SIGN(pq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(pq)) THEN 2 
    END As ord, 
    -- quantity is difference 
    CASE 
     WHEN (SIGN(nq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(nq)) THEN nq + quantity 
     WHEN (SIGN(pq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(pq)) THEN pq + quantity 
    END As quantity 
FROM t1 
WHERE 
    -- Find differences more 
    1 = CASE 
      WHEN (SIGN(nq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(nq)) THEN 1 
      WHEN (SIGN(pq) <> SIGN(quantity)) AND (ABS(quantity) > ABS(pq)) THEN 1 
      ELSE 0 
     END) 
SELECT 
    -- Use new values for id 
    ROW_NUMBER() OVER (ORDER BY id, ord) As id, 
    m_id, quantity 
FROM t2;