Question

我有记录行历史的表。我想获得每一行的最新版本。它有我可以使用的时间戳表记录如下所示： -

5002113 691455384259    0   2   123111111   BG32    che2ck@gmail.com    2017-05-18 15:12:40.967
5002113 671797299758    0   2   12312311    BTY2    che4ck@gmail.com    2017-05-15 14:42:53.690
5002113 212212957483    0   2   1231412111  RTE     che3ck@gmail.com    2017-05-14 16:16:59.110
5002113 671797299758    0   2   123111111   BY32    check@gmail.com     2017-05-14 16:12:58.923
5002113 691455384259    0   2   123111111   BIT32   chec4k@gmail.com    2017-05-14 14:35:25.333
5003183 594534755753    1   2   555555555   LS42    tha3ur@gmail.com    2017-05-12 17:42:20.457
5002114 594534755753    1   2   234324121   fIS72   trtakur@gmail.com   2017-05-12 17:35:20.527

查询： -

Select 
  ac.strID,
  sp.strPin,
  sp.blnActive,
  CASE 
    WHEN strType = 'Email' and strRType = 'Email' THEN 2 
    WHEN strType = 'Paper' and strRType = 'Email' THEN 0
    WHEN strType = 'Ws' and strRType = 'Ws' THEN 1
  END as strInterfaceType,
  id.strID,
  sp.strFXType,
  sp.strEmail,
  sp.dtmChanged
from employer_profile sp 
inner join employer_id id
  on  sp.lngCkey  =   id.LNGCKEY 
Inner join employer_account ac
  on sp.lngAKey = ac.lngKey
order by dtmChanged desc

最终结果需要： -

5002113 691455384259    0   2   123111111   BG32    che2ck@gmail.com    2017-05-18 15:12:40.967
5003183 594534755753    1   2   555555555   LS42    tha3ur@gmail.com    2017-05-12 17:42:20.457
5002114 594534755753    1   2   234324121   fIS72   trtakur@gmail.com   2017-05-12 17:35:20.527

Answer 1

只需添加内部联接

inner join
(select max(dtmChanged) ts from employer_profile) t on t.ts = sp.dtmChanged

Answer 2

你可以使用带有以下关系的前1：

Select top (1) with ties * from
(
   ...--your query without order by clause
) a
order by row_number() over(partition by strID order by dtmChanged desc)

包括您的查询，如下所示：

Select top (1) with ties * from
(
    Select 
      ac.strID,
      sp.strPin,
      sp.blnActive,
      CASE 
        WHEN strType = 'Email' and strRType = 'Email' THEN 2 
        WHEN strType = 'Paper' and strRType = 'Email' THEN 0
        WHEN strType = 'Ws' and strRType = 'Ws' THEN 1
      END as strInterfaceType,
      id.strID,
      sp.strFXType,
      sp.strEmail,
      sp.dtmChanged
    from employer_profile sp 
    inner join employer_id id
      on  sp.lngCkey  =   id.LNGCKEY 
    Inner join employer_account ac
      on sp.lngAKey = ac.lngKey
) a
order by row_number() over(partition by strID order by dtmChanged desc)

在SQL中获取表中的最新版本

2 个答案: