Question

如果以下MySQL表包含带有相关金额的借方或贷方“操作”，如何选择所有具有非零“余额”的CLIENT_ID？我已尝试将表格加入到自身中以计算所有借记和贷记总额，但某些内容无效。

CLIENT_ID    ACTION_TYPE    ACTION_AMOUNT
1            debit          1000
1            credit         100
1            credit         500
2            debit          1000
2            credit         1200
3            debit          1000
3            credit         1000
4            debit          1000

我的MySQL查询不起作用：

SELECT 
    client_id,
    SUM(t_debits) AS debits, 
    SUM(t_credits) AS credits, 
    SUM(t_debits)-SUM(t_credits) AS balance
FROM table_name AS t_debits
LEFT JOIN table_name AS t_credits ON t_credits.client_id=t_debits.client_id
WHERE 
    t_debits.action_type='debit'
    AND t_credits.action_type='credit'
    AND balance!=0
GROUP BY t_debits.client_id, t_credits.client_id;

我期待的结果是：

CLIENT_ID    DEBITS    CREDITS    BALANCE
1            1000      600        400
2            1000      1200       -200
4            1000      0          1000

我不知道还有什么可以尝试的。任何帮助都会很棒。

Answer 1

DROP TABLE IF EXISTS my_table;

CREATE TABLE my_table
(transaction_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,client_id INT NOT NULL
,action_type VARCHAR(12) NOT NULL
,action_amount INT NOT NULL
);

INSERT INTO my_table(client_id,action_type,action_amount) VALUES
(1            ,'debit',         1000),
(1            ,'credit',         100),
(1            ,'credit',         500),
(2            ,'debit',          1000),
(2            ,'credit',         1200),
(3            ,'debit',          1000),
(3            ,'credit',         1000),
(4            ,'debit',          1000);


SELECT client_id
     , SUM(COALESCE(CASE WHEN action_type = 'debit' THEN action_amount END,0)) total_debits
     , SUM(COALESCE(CASE WHEN action_type = 'credit' THEN action_amount END,0)) total_credits
     , SUM(COALESCE(CASE WHEN action_type = 'debit' THEN action_amount END,0)) 
     - SUM(COALESCE(CASE WHEN action_type = 'credit' THEN action_amount END,0)) balance 
  FROM my_table 
 GROUP  
    BY client_id
HAVING balance <> 0;


+-----------+--------------+---------------+---------+
| client_id | total_debits | total_credits | balance |
+-----------+--------------+---------------+---------+
|         1 |         1000 |           600 |     400 |
|         2 |         1000 |          1200 |    -200 |
|         4 |         1000 |             0 |    1000 |
+-----------+--------------+---------------+---------+

Answer 2

您需要使用case声明

select client_id, debits, credits, debits-credits as balance
from (SELECT 
client_id,
SUM(case when ACTION_TYPE='debit' then action_amount else 0 end) AS debits, 
SUM(case when ACTION_TYPE='credit' then action_amount else 0 end) AS credits
FROM categories 
GROUP BY client_id) a
where debits-credits<>0;

Fiddle

Answer 3

使用这个最小的查询

        select CLIENT_ID,
                    sum(if(ACTION_TYPE='credit',ACTION_AMOUNT,0)) as credit,
                    sum(if(ACTION_TYPE='debit',ACTION_AMOUNT,0)) as debit,
                    sum(if(ACTION_TYPE='credit',ACTION_AMOUNT,-1*ACTION_AMOUNT)) as balance
        FROM YOUR_TABLE
        GROUP BY CLIENT_ID

使用MySQL计算单个表中借方和贷方的余额

3 个答案: