SQLite選擇內更新

Question

所以有2個表，Transactions與created_at列和Transaction_associations與amount和remaining_balance列等。我需要計算amount列中的運行總和（總計），顯然按created_at列排序。唯一的問題是，我需要獲得所有在之前創建的事務的SUM當前正在計算的事務。我將需要在更新查詢內部選擇一個SELECT a current_transactions表以便獲得當前的created_at日期。但我不能。我錯過了什麼嗎？這種方法有其他選擇嗎？

UPDATE Transaction_associations SET remaining_balance = 
( 
    SELECT SUM (Transaction_associations.amount) 
    FROM Transactions 
    JOIN Transaction_associations ON Transactions.id = transaction_id 
    WHERE created_at <= current_transactions.created_at // here 
) 
WHERE id IN 
(
    SELECT id 
    FROM Transaction_associations 
    JOIN Transactions ON Transactions.id = transaction_id 
    WHERE created_at >= '2014-11-24' 
) 

編輯：，將實施例。

Transactions  Transaction_associations 
created_at  amount  remaining_balance 
2014-02-01  100  100 
2014-03-01  50  150 
2014-04-01  205  355 

後來編輯：對SQLFiddle使用添加完整的代碼。我把它換成Transaction_associations與SUM TA2，因爲它抱怨的misuse of aggregate: SUM()

DROP TABLE IF EXISTS Transactions; 
DROP TABLE IF EXISTS Transaction_associations; 
CREATE TABLE Transactions (id integer, created_at text); 
CREATE TABLE Transaction_associations (id integer, amount integer, remaining_balance integer, transaction_id integer); 

    INSERT INTO Transactions VALUES (1,'2015'); 
    INSERT INTO Transactions VALUES (2,'2014'); 
    INSERT INTO Transactions VALUES (3,'2013'); 
    INSERT INTO Transactions VALUES (4,'2012'); 
    INSERT INTO Transactions VALUES (5,'2010'); 
    INSERT INTO Transaction_associations VALUES (6, 100, 0, 1); 
    INSERT INTO Transaction_associations VALUES (7, 20, 0, 2); 
    INSERT INTO Transaction_associations VALUES (8, 3, 0, 3); 
    INSERT INTO Transaction_associations VALUES (9, 40, 0, 4); 
    INSERT INTO Transaction_associations VALUES (10, 500, 0, 5); 



UPDATE Transaction_associations 
SET remaining_balance = 
(
    SELECT SUM(TA2.amount) 
    FROM Transactions 
    JOIN Transaction_associations AS TA2 ON Transactions.id = TA2.transaction_id 
    WHERE created_at <= (SELECT created_at 
         FROM Transactions 
         WHERE id = TA2.transaction_id) 
) 
WHERE transaction_id IN 
(
    SELECT id 
    FROM Transactions 
    WHERE created_at >= '2013' 
); 

SELECT * from Transactions join Transaction_associations on Transactions.id = Transaction_associations.transaction_id; 

這導致，這是錯誤的：

1 2015 6 100 663 1 
2 2014 7 20 663 2 
3 2013 8 3 663 3 
4 2012 9 40 0 4 
5 2010 10 500 0 5 

結果應該是：

1 2015 6 100 663 1 
2 2014 7 20 563 2 
3 2013 8 3 543 3 
4 2012 9 40 0 4 
5 2010 10 500 0 5 

Answer 1

要多次使用相同的表名，請重命名其中的一個。這對於UPDATE來說是不可能的，所以你必須在SELECT中這樣做。 要查找相應的時間戳，請使用另一個子查詢。 加上一些簡化，這將變爲：

UPDATE Transaction_associations 
SET remaining_balance = 
(
    SELECT SUM(TA2.amount) 
    FROM Transactions 
    JOIN Transaction_associations AS TA2 ON Transactions.id = TA2.transaction_id 
    WHERE created_at <= (SELECT created_at 
         FROM Transactions 
         WHERE id = Transaction_associations.transaction_id) 
) 
WHERE transaction_id IN 
(
    SELECT id 
    FROM Transactions 
    WHERE created_at >= '2014-11-24' 
);