Question

我正在尝试编写一个查询，将重复的客户端记录合并到一个记录中。现在我只是构建一个映射表来了解我应该用什么映射。

这是我写的两个函数来帮助我

CREATE FUNCTION FindDuplicateClients ()
RETURNS TABLE AS RETURN 
(
    select distinct CLIENT_GUID 
    from CLIENTS c
    inner join
    (
        select FIRST_NAME, LAST_NAME, HOME_PHONE
        from CLIENTS
        group by FIRST_NAME, LAST_NAME, HOME_PHONE
        having COUNT(*) > 1
    ) t on c.FIRST_NAME = t.FIRST_NAME and c.LAST_NAME = t.LAST_NAME and c.HOME_PHONE = t.HOME_PHONE)
go

--Find other clients that map to this client
CREATE FUNCTION FindDuplicateClientsByClient (@Client uniqueidentifier)
RETURNS TABLE AS RETURN 
(
    select distinct CLIENT_GUID 
    from CLIENTS c
    inner join
    (
        select x.FIRST_NAME, x.LAST_NAME, x.HOME_PHONE
        from CLIENTS x
        inner join 
        (
            select FIRST_NAME, LAST_NAME, HOME_PHONE
            from CLIENTS
            where CLIENT_GUID = @Client
        ) y on x.FIRST_NAME = y.FIRST_NAME and x.LAST_NAME = y.LAST_NAME and x.HOME_PHONE = y.HOME_PHONE
        group by x.FIRST_NAME, x.LAST_NAME, x.HOME_PHONE
        having COUNT(*) > 1
    ) t on c.FIRST_NAME = t.FIRST_NAME and c.LAST_NAME = t.LAST_NAME and c.HOME_PHONE = t.HOME_PHONE
    where CLIENT_GUID <> @Client)
go

第一个函数成功返回有超过1个记录的所有CLIENT_GUID，第二个函数返回GUID并返回共享＆＃34;公共信息＆＃34的所有其他guid ; （在这种情况下，名字，姓氏和家庭电话）

问题是填写我的映射表。我有一些规则需要遵循以优先考虑一些重复项。例如，任何拥有交易的人都需要更改CLIENT_GUID，但他们可以将其他GUID合并到其中（如果其他GUID没有交易）

--Create Mapping table
select CLIENT_GUID, CAST(null as uniqueidentifier) as NEW_CLIENT_GUID
into #mapping
from FindDuplicateClients()

--Do not map people who have transactions
update #mapping
set NEW_CLIENT_GUID = CLIENT_GUID
where CLIENT_GUID in (select CLIENT_GUID from trnHistory)

现在，我正在遇到麻烦。我不知道如何获取在上一个查询中设置NEW_CLIENT_GUID的人员列表，针对该GUID运行FindDuplicateClientsByClient，并将NEW_CLIENT_GUID的任何结果设置为{ {1}}在不使用游标的情况下输入函数。

这是我使用游标

提出的方法

NEW_CLIENT_GUID

对我来说，迭代declare cur cursor LOCAL FAST_FORWARD for select NEW_CLIENT_GUID from #mapping where NEW_CLIENT_GUID is not null declare @NEW_CLIENT_GUID uniqueidentifier open cur fetch next from cur into @NEW_CLIENT_GUID while @@fetch_status = 0 begin update #mapping set NEW_CLIENT_GUID = @NEW_CLIENT_GUID where CLIENT_GUID in (select CLIENT_GUID from FindDuplicateClientsByClient(@NEW_CLIENT_GUID)) --Find duplicates to this record and NEW_CLIENT_GUID is null --Do not reassign values that are already set (ie: duplicates that have transactions) fetch next from cur into @NEW_CLIENT_GUID end close cur deallocate cur中具有值集的每个结果对我来说似乎不正确。这样做的正确方法是什么？我使用的是SQL Server 2008 R2，但我更喜欢它与SQL Server 2005兼容。

Answer 1

已经有两天没有答案，我只是坚持使用我的光标解决方案，因为它的性能足以满足我的需要。

当我不得不循环第二次寻找未在上一次传递中映射的人时，我确实使用了不同的方法，但它只是一个与前一个光标完全相同的while循环。

declare @tmpGuid uniqueidentifier
select @tmpGuid = CLIENT_GUID from #mapping where NEW_CLIENT_GUID is null 
while @@ROWCOUNT > 0
begin   
  --Set the first unset guid to itself
  update #mapping
  set NEW_CLIENT_GUID = @tmpGuid
  where CLIENT_GUID = @tmpGuid

  --set all other duplicates to the guid we just used.
  update #mapping
  set NEW_CLIENT_GUID = @tmpGuid
  where CLIENT_GUID in (select CLIENT_GUID from FindDuplicateClientsByClient(@tmpGuid))
       and NEW_CLIENT_GUID is null

  --get next guid
  select @tmpGuid = CLIENT_GUID from #mapping where NEW_CLIENT_GUID is null 
end
set nocount off
go

从表值函数的输出更新一组数据

1 个答案: