Question

SELECT mob_no,

  (SELECT max(str_to_date(debit_date,'%d/%m/%Y'))
   FROM client_debit_bal
   WHERE mob_no='".$mobno."') AS date,
       sum(debit_amt) AS debit
FROM client_debit_bal
WHERE date_format(str_to_date(debit_date,'%d/%m/%Y'), '%Y-%m-%d')= date

实际上这里date是一个别名变量，我无法用于条件。请帮我解决这个问题。

示例数据

-----------------------------------
date       | cre_amount  |   mob_no
------------------------------------
23/01/2013 |    100     | 123456
------------------------------------
24/01/2013 |    500     | 123456
------------------------------------
25/01/2013 |    500     | 123456
------------------------------------
26/01/2013 |    900     | 123456
------------------------------------
29/01/2013 |    1000     | 123456
------------------------------------
29/01/2013 |    1300     | 123456
------------------------------------
29/01/2013 |    1200     | 123456
------------------------------------

预期输出为max(date)和sum(cre_amount)，结果为3500

（表示选择最大date并从最长日期返回cre_amount的总和）

Answer 1

简单地使用

select DATE_FORMAT(max(cast(str_to_date(`date`, '%d/%m/%Y') as date)),'%d/%m/%Y'),
   sum(cre_amount) from table1 where date=(select DATE_FORMAT(max(cast(str_to_date(`date`, '%d/%m/%Y') as date)),'%d/%m/%Y') 
     from table1)

如何在mysql中使用条件的别名变量？

1 个答案: