0

我有这样的数据。

REPORTER    SUMMARY                CREATED          UPDATED status  servicetype  
e159299 Route card from August  7/29/2013   22:46.0    5    New Route Card
e159299 I have returned the     6/11/2013   32:09.7    5    Cancel Route Card
e159324 New Route Card: RBI     1/2/2013    00:51.0    5    New Route Card
e159324 Hi, I would require     10/30/2013  35:23.0    5    New Route Card
e159299 Cancel Route Card       4/30/2013   53:26.2    5    Cancel Route Card

我需要获取给定记者的最新记录条目。即我需要为记者进行分组，并且需要获取组合创建字段的最新记录。

我的输出必须是这样的。 

 e159299    Route card from August  7/29/2013   22:46.0    5    New Route Card  
 e159324    Hi, I would require     10/30/2013  35:23.0    5    New Route Card
4

3 回答 3

3

分析函数非常适合这种查询：

select *
from (
   select reporter
   ,      summary
   ,      created
   ,      updated_status
   ,      servicetype
   ,      max(created) over (partition by reporter) last_created
   from   yout_table t)
where created = last_created;
于 2013-11-28T08:20:37.877 回答
0

分析功能是为此而设计的 - 只是GROUP BY适当的列（在这种情况下REPORTER）并用于MAX( <column_name> ) KEEP ( DENSE_RANK LAST ORDER BY <ordering_column> )其他每一行。

SQL小提琴

Oracle 11g R2 模式设置：

CREATE TABLE tbl ( REPORTER, SUMMARY, CREATED, UPDATED, status, servicetype ) AS
          SELECT 'e159299', 'Route card from August', '7/29/2013',  '22:46.0', 5, 'New Route Card' FROM DUAL
UNION ALL SELECT 'e159299', 'I have returned the',    '6/11/2013',  '32:09.7', 5, 'Cancel Route Card' FROM DUAL
UNION ALL SELECT 'e159324', 'New Route Card: RBI',    '1/2/2013',   '00:51.0', 5, 'New Route Card' FROM DUAL
UNION ALL SELECT 'e159324', 'Hi, I would require',    '10/30/2013', '35:23.0', 5, 'New Route Card' FROM DUAL
UNION ALL SELECT 'e159299', 'Cancel Route Card',      '4/30/2013',  '53:26.2', 5, 'Cancel Route Card' FROM DUAL;

查询 1：

SELECT REPORTER,
       MAX( SUMMARY     ) KEEP ( DENSE_RANK LAST ORDER BY TO_DATE( CREATED, 'MM/DD/YYYY' ) ) AS SUMMARY,
       MAX( CREATED     ) KEEP ( DENSE_RANK LAST ORDER BY TO_DATE( CREATED, 'MM/DD/YYYY' ) ) AS CREATED,
       MAX( UPDATED     ) KEEP ( DENSE_RANK LAST ORDER BY TO_DATE( CREATED, 'MM/DD/YYYY' ) ) AS UPDATED,
       MAX( status      ) KEEP ( DENSE_RANK LAST ORDER BY TO_DATE( CREATED, 'MM/DD/YYYY' ) ) AS status,
       MAX( servicetype ) KEEP ( DENSE_RANK LAST ORDER BY TO_DATE( CREATED, 'MM/DD/YYYY' ) ) AS servicetype
FROM tbl
GROUP BY REPORTER

结果：

| REPORTER |                SUMMARY |    CREATED | UPDATED | STATUS |    SERVICETYPE |
|----------|------------------------|------------|---------|--------|----------------|
|  e159299 | Route card from August |  7/29/2013 | 22:46.0 |      5 | New Route Card |
|  e159324 |    Hi, I would require | 10/30/2013 | 35:23.0 |      5 | New Route Card |
于 2013-11-28T08:59:26.827 回答
-1

尝试这个...

SELECT * FROM table ORDER BY CREATED DESC LIMIT 0,2

此查询适用于 mysql 数据库

于 2013-11-28T08:27:20.493 回答