Question

我对此感到困惑：

SELECT request_id, SUM( cc_amount ) AS amt,
       DATE_FORMAT( transaction_datetime,  '%b %y' ) AS tdate
  FROM ee_request_cc
 GROUP BY DATE_FORMAT( transaction_datetime,  '%b %y' ) 

UNION 

SELECT request_id, SUM( request_amount ) AS amt,
       DATE_FORMAT( transaction_date,  '%b %y' ) AS tdate
  FROM ee_request_paypal
 GROUP BY DATE_FORMAT( transaction_date,  '%b %y' )

我得到了：

id    amt    tdate
20  86.00   Mar 12
80   5.00   Apr 12
23  55.00   Mar 12

而我想在3月和4月添加所有金额，如：

id     amt   tdate
20  141.00  Mar 12
80    5.00  Apr 12

请建议我查询中的更改。

Answer 1

试试这个：

select sum(amt), DATE_FORMAT(tdate, '%b %y') from (
    SELECT amount1 AS amt, transaction_dt AS tdate
    FROM table1
    UNION ALL
    SELECT request_amount, tr_date
    FROM table2
) s
GROUP BY YEAR(tdate), MONTH(tdate)

请注意，您不应该从分组结果中获取ID ...您会选择哪一个？

同样按数字分组必须比将日期转换为字符串然后按字符串分组更快。

Answer 2

你使用一个englobing SELECT和amt和GROUP BY tdate

SELECT id, SUM(amt) as samt, tdate
FROM (YOUR_ABOBE_QUERY) AS thequery
GROUP BY thequery.tdate

Answer 3

您需要获取所有结果，然后执行聚合：

SELECT table_both.request_id, table_both.tdate, SUM(table_both.amount) AS amt
FROM (SELECT request_id, cc_amount AS amt, DATE_FORMAT(transaction_datetime,'%b %y') AS tdate
    FROM table1 

    UNION ALL --Don't remove the duplicates

    SELECT request_id, request_amount, DATE_FORMAT(transaction_date,'%b %y')
    FROM table2) table_both
GROUP BY table_both.request_id, table_both.tdate --You don't need to add the format function in the group by

联合两个查询以获取mysql中的结果

3 个答案: