您如何在MSSQL的where子句中使用变量。 @UI变量更改并且不是静态的，我在sql中这样做会出错。当我想运行更新或插入语句时，它适用于列名。
declare @UI varchar(50)
set @UI = 'IDNumber'
exec 'set @ClientExist = isnull((select top 1 clientid from Clients
where '+ @UI +' = ''6001016119085''
or '+ @UI +' = ''None''
and cancelled <> 1
order by ClientID desc),0)'
declare @sql nvarchar(max)
set @sql = N'declare @StagingID int
declare @ClientID int
declare @VehicleID int
declare @tempID1 int
declare @tempID2 int
declare @ClientExist int
set @tempID1 = 0
set @tempID2 = 0
set @ClientID = 0
set @VehicleID = 0
declare @rows integer
declare @column1 nvarchar(500)
declare @column2 nvarchar(500)
declare @column3 nvarchar(500)
declare @column4 nvarchar(500)
declare @column5 nvarchar(500)
declare @column6 nvarchar(500)
declare @column7 nvarchar(500)
declare @column8 nvarchar(500)
declare @column9 nvarchar(500)
declare @column10 nvarchar(500)
declare @column11 nvarchar(500)
declare @column12 nvarchar(500)
declare @column13 nvarchar(500)
declare @column14 nvarchar(500)
declare @column15 nvarchar(500)
declare @column16 nvarchar(500)
declare @column17 nvarchar(500)
declare @column18 nvarchar(500)
declare @column19 nvarchar(500)
declare @column20 nvarchar(500)
declare @column21 nvarchar(500)
declare @column22 nvarchar(500)
declare @column23 nvarchar(500)
declare @column24 nvarchar(500)
declare @column25 nvarchar(500)
declare @column26 nvarchar(500)
declare @column27 nvarchar(500)
declare @column28 nvarchar(500)
declare @column29 nvarchar(500)
declare @column30 nvarchar(500)
declare @column31 nvarchar(500)
declare @column32 nvarchar(500)
declare @column33 nvarchar(500)
declare @column34 nvarchar(500)
declare @column35 nvarchar(500)
declare @column36 nvarchar(500)
declare @column37 nvarchar(500)
declare @column38 nvarchar(500)
declare @column39 nvarchar(500)
declare @column40 nvarchar(500)
declare @column41 nvarchar(500)
declare @column42 nvarchar(500)
declare @column43 nvarchar(500)
declare @column44 nvarchar(500)
declare @column45 nvarchar(500)
declare @column46 nvarchar(500)
declare @column47 nvarchar(500)
declare @column48 nvarchar(500)
declare @column49 nvarchar(500)
declare @column50 nvarchar(500)
Select *
into #temp
from Staging
where brokerID = '+ @BrokerID +' and ImportStatus <> ''Processed''
set @rows = (select COUNT(1) from #temp)
WHILE @rows > 0
BEGIN
set @tempID2 = @tempID1
select @StagingID = StagingID
,@column1 = column1
,@column2 = column2
,@column3 = column3
,@column4 = column4
,@column5 = column5
,@column6 = column6
,@column7 = column7
,@column8 = column8
,@column9 = column9
,@column10 = column10
,@column11 = column11
,@column12 = column12
,@column13 = column13
,@column14 = column14
,@column15 = column15
,@column16 = column16
,@column17 = column17
,@column18 = column18
,@column19 = column19
,@column20 = column20
,@column21 = column21
,@column22 = column22
,@column23 = column23
,@column24 = column24
,@column25 = column25
,@column26 = column26
,@column27 = column27
,@column28 = column28
,@column29 = column29
,@column30 = column30
,@column31 = column31
,@column32 = column32
,@column33 = column33
,@column34 = column34
,@column35 = column35
,@column36 = column36
,@column37 = column37
,@column38 = column38
,@column39 = column39
,@column40 = column40
,@column41 = column41
,@column42 = column42
,@column43 = column43
,@column44 = column44
,@column45 = column45
,@column46 = column46
,@column47 = column47
,@column48 = column48
,@column49 = column49
,@column50 = column50
from #temp
--Check for duplicate client, insert or update then
declare @UIvalue varchar(50)
set @UIvalue = (select StageColumn from ColumnStructure where [uniqueidentifier] = 1)
set @ClientExist = isnull((select top 1 clientid from Clients where '+ @UI +' = @UIvalue or '+ @UI +' = ''None'' and cancelled <> 1 order by ClientID desc),0)
if @ClientExist = 0
Begin
if len(''' + @ClientCCol + ''') > 0 and len(''' + @ClientSCol + ''') > 0
Begin
Insert into Clients (' + @ClientCCol + ', System, DateAdded) Values (@' + @ClientSCol + ', ''Import'', getdate())
set @ClientID = (select @@Identity)
End
End
ELSE
Begin
Update Clients set ' + @UpdateC + ' where clientid = @ClientExist
End
set @tempID1 = (select @@identity)
if @ClientID > 0
Begin
Update Clients set Province = (select p.ProvinceID from Provinces p inner join clients c on c.ProvinceDesc = p.Province where clientid = @ClientID and p.Province = c.ProvinceDesc)
,Country = (select co.CountryID from Countrys co inner join clients c on c.CountryDesc = co.Country where clientid = @ClientID and co.Country = c.CountryDesc)
,Title = (select t.TitleID from Titles t inner join clients c on c.TitleDesc = t.Title where clientid = @ClientID and t.Title = c.TitleDesc)
where ClientID = @ClientID
End
declare @Registration varchar(100)
declare @EngineNum varchar(100)
set @Registration = (select StageColumn from ColumnStructure where ClientsCol = ''Registration'' and BrokerID = ' + @BrokerID + ')
set @EngineNum = (select StageColumn from ColumnStructure where ClientsCol = ''EngineNum'' and BrokerID = ' + @BrokerID + ')
--Check for duplicate vehicle, insert or update then
set @VehicleID = isnull((select top 1 isnull(VehicleID, 0) from VehicleInformation where clientid = @ClientID and Registration = @Registration and EngineNum = @EngineNum order by VehicleID desc),0)
if @VehicleID = 0
Begin
if len(''' + @VehicleCCol + ''') > 0 and len(''' + @VehicleSCol + ''') > 0
Begin
Insert into VehicleInformation (' + @VehicleCCol + ', ClientID) Values (@' + @VehicleSCol + ', @ClientID)
set @VehicleID = (select @@Identity)
End
End
Else
Begin
Update VehicleInformation set ' + @UpdateV + ' where VehicleID = @VehicleID
End
if @VehicleID > 0
Begin
Update VehicleInformation set Make = (select vm.MakeID from VehicleMake vm inner join VehicleInformation v on v.Makedesc = vm.Make where v.VehicleID = @VehicleID and vm.make = v.makedesc) where VehicleID = @VehicleID
End
if (@tempID1 <> 0 or @tempID1 is not null) and @tempID1 > @tempID2
update dbo.Staging
set DateAdded = getdate(), ImportStatus = ''Processed''
where StagingID = @StagingID
Else
update dbo.Staging
set DateAdded = getdate(), ImportStatus = ''Error Occured''
where StagingID = @StagingID
delete from #temp where StagingID = @StagingID
set @rows = (select COUNT(1) from #temp)
set @VehicleID = 0
set @ClientID = 0
END
drop table #temp'
exec (@sql)
这是我在＆＃39; + +＆＃39;中运行所有变量的实际查询。即时通讯从外面调用..现在这确实有效，但当我把@UI放入其中时开始给我留下错误...其中的chr（39）不会编译，所以@gordon会在服务器2008中解决帮助问题，并且我是否必须声明引号内的所有变量，如@gordon，并使用@Clientid的示例
答案 0 :(得分：7)
使用sp_executesql。这样，您可以将变量传入和传出语句。在您的情况下，语法是这样的：
declare @UI varchar(50);
declare @ClientId varchar(50);
set @UI = 'IDNumber';
declare @sql nvarchar(max);
SET @sql = N' select top 1 @ClientId = clientid
from Clients
where '+ QUOTENAME(@UI) + N' = ''6001016119085'' or '
+ QUOTENAME(@UI) + N' = ''None'' and cancelled <> 1';
exec sp_executesql @sql
, N'@ClientId varchar(50) OUTPUT'
, @ClientId = @ClientId OUTPUT
set @ClientExist = coalesce(@ClientId, 0);
sp_executesql的文档是here。
答案 1 :(得分：2)
如果它的sqlserver 2000中sp_executesql不起作用，请创建临时表并将数据存储在那里
declare @UI varchar(50)
set @UI = 'IDNumber'
create table #result ( ClientExist bit ) -- temp table to store the data
declare @SQL varchar(4000)
set @SQL =
'insert into #result (ClientExist)
select isnull((select top 1 clientid
from Clients where '+ @UI +' = ''6001016119085'' or '+ @UI +' = ''None'' and cancelled <> 1 order by ClientID desc),0)'
execute(@SQL)
declare @ClientExist bit
SET @ClientExist = (select top 1 ClientExist from #result)
我从问题＆＃34复制了select;＆＃34;，我通常使用chr（39）转义单引号，所以它会是：...where '+ @UI +' = '+chr(39)+'6001016119085'+chr(39)+' or '...