MySQL groupwise MAX() 返回意外结果

Question

表:贷款

Loan_no     Amount        SSS_no              Loan_date

7           700.00        0104849222          2010-01-03 
8           200.00        0104849222          2010-02-28
9           300.00        0119611199          2010-11-18
10          150.00        3317131410          2012-11-28
11          600.00        0104849222          2011-01-03
14          175.00        3317131410          2012-12-05
15          260.00        3317131410          2013-02-08
16          230.00        0104849222          2013-03-06
17          265.00        0119611199          2011-04-30
18          455.00        3317131410          2013-03-10

---

期望的结果:

我想检索最近可用的贷款由每个人(通过他们的 SSS 号码识别)。这结果应该如下:

Loan_no           Amount                SSS_no                Loan_date

16                230.00              0104849222              2013-03-06
17                265.00              0119611199              2011-04-30
18                455.00              3317131410              2013-03-10

---

已使用查询#1:

选择 *
FROM贷款
按 SSS_no 分组
按 Loan_date DESC 排序

MySQL 结果

Loan_no             Amount              SSS_no                  Loan_date

10                  150.00            3317131410                2012-11-28
9                   300.00            0119611199                2010-11-18
7                   700.00            0104849222                2010-01-03

---

使用的查询#2:

SELECT Loan_no, Amount, SSS_no, max(Loan_date)
FROM贷款
按 SSS_no 分组

MySQL 结果

Loan_no            Amount                SSS_no                Loan_date

7                  700.00                0104849222            2013-03-06
9                  300.00                0119611199            2011-04-30
10                 150.00                3317131410            2013-03-10

谁能帮我解决我的问题？谢谢。

Answer 1

试试这个:

SELECT l1.*
FROM loan AS l1
INNER JOIN
(
   SELECT SSS_no, MAX(Loan_date) LatestDate
   FROM loan
   GROUP BY SSS_no
) AS l2  ON l1.SSS_no    = l2.SSS_no 
        AND l1.loan_date = l2.LatestDate;

SQL Fiddle Demo

这会给你:

| LOAN_NO | AMOUNT |     SSS_NO |  LOAN_DATE |
----------------------------------------------
|      16 |    230 |  104849222 | 2013-03-06 |
|      17 |    265 |  119611199 | 2011-04-30 |
|      18 |    455 | 3317131410 | 2013-03-10 |