动态SQL将局部变量作为表变量读取？

Question

这不是关于使用表变量-而是关于在动态SQL游标中使用局部变量来携带db地址，理论上它的工作原理如下：-假设已经声明了全局变量@sql、AnalysisLocation和@sp_executeSql。

ALTER PROCEDURE [dbo].[sp_AggregateCompliance_Report]
@clientID int,
@InvScrDBLocation nvarchar(250),
@JoinFilter nvarchar(max) = '',
@Criteria nvarchar(max) = '',
@Year int = NULL

as

declare @sql nvarchar(4000)


set @sql = '
IF EXISTS (SELECT * FROM sys.tables WHERE name = ''tmp_Aggregate_Compliance_counts'')
TRUNCATE TABLE tmp_Aggregate_Compliance_counts
ELSE
CREATE TABLE tmp_Aggregate_Compliance_counts (
pfc_fk_prv_pkid int,
RxYear int,
RxMonth int,
Compliance decimal (6,5))
' print @sql  EXEC sp_executesql @sql


SET @Criteria = isnull(case when @Criteria like 'WHERE %' then 'AND '+substring(@criteria,7,len(@criteria)-6) else @Criteria end ,'')
SET @Year = isnull(@year, year(getdate())-1)


 set @sql = '
DECLARE @fk_cli_pkid INT
    ,   @ServerAndDB_for_pfcAppended nvarchar(100)

DECLARE client_set CURSOR FOR
SELECT  DISTINCT mtx.fk_cli_pkid, SettingValue+ ''.dbo.pfc_appended''
FROM    mtx_ComplianceAndEarlyRefill_tracking AS mtx
JOIN    prola7.Invoice_Screens.dbo.client_definition AS def
ON      mtx.fk_cli_pkID = def.fk_cli_pkid
AND     fk_lkSettings_pkID  = 45
AND     RecordStatus = 1 

OPEN    client_set

FETCH next FROM client_set
INTO    @fk_cli_pkid, @ServerAndDB_for_pfcAppended

WHILE   @@FETCH_STATUS = 0 BEGIN

INSERT INTO tmp_Aggregate_Compliance_counts (pfc_fk_prv_pkid, RxYear, RxMonth, Compliance)

SELECT  pfc.pfc_fk_prv_pkid
    ,   year(mtx.pfc_dateofservice) AS RxYear
    ,   0 AS RxMonth
    ,   cast(mtx.Compliance as decimal (6,5))
FROM    mtx_ComplianceAndEarlyRefill_tracking AS mtx
LEFT OUTER JOIN @ServerAndDB_for_pfcAppended AS pfc
ON      mtx.pp_clientfile   = pfc.pp_clientfile
AND     mtx.pp_mirror_pkid  = pfc.pp_mirror_pkid
AND     mtx.fk_cli_pkid     = @fk_cli_pkid
'+@JoinFilter+'
WHERE   pfc.pfc_status = 0
AND     year(mtx.pfc_dateofservice) = '+cast(@Year as nvarchar)+'
'+@Criteria+'
GROUP BY pfc.pfc_fk_prv_pkid, year(mtx.pfc_dateofservice)


FETCH next FROM client_set
INTO    @fk_cli_pkid, @ServerAndDB_for_pfcAppended

END

CLOSE client_set
DEALLOCATE client_set
' print @sql  EXEC sp_executesql @sql

这在编译动态代码时不会产生语法错误，但是在调用此过程时:Msg1087，Level 15，State 2，第27行必须声明表变量"@ServerAndDB_for_pfcAppended“。

当我使用这种类型的结构从过程外部将location变量作为全局变量传入时，它会正确地接受它，但是作为一个局部变量，它似乎默认假定它是一个表变量。

我不想创建表变量。这是一个不可能的结构吗？

Answer 1

该错误是由于您试图使用参数化的表名造成的。这是不可能的，只要表名应该是一个参数，就会使用动态查询，基本上就像这样：

SET @sql = 'SELECT … FROM ' + @tablename + ' WHERE …'

我认为，在您的情况下，游标应该从动态查询中删除，除了使用参数化表名的部分。类似下面这样的代码应该可以：

ALTER PROCEDURE [dbo].[sp_AggregateCompliance_Report]
@clientID int,
@InvScrDBLocation nvarchar(250),
@JoinFilter nvarchar(max) = '',
@Criteria nvarchar(max) = '',
@Year int = NULL

as

declare @sql nvarchar(4000)


set @sql = '
IF EXISTS (SELECT * FROM sys.tables WHERE name = ''tmp_Aggregate_Compliance_counts'')
TRUNCATE TABLE tmp_Aggregate_Compliance_counts
ELSE
CREATE TABLE tmp_Aggregate_Compliance_counts (
pfc_fk_prv_pkid int,
RxYear int,
RxMonth int,
Compliance decimal (6,5))
' print @sql  EXEC sp_executesql @sql


SET @Criteria = isnull(case when @Criteria like 'WHERE %' then 'AND '+substring(@criteria,7,len(@criteria)-6) else @Criteria end ,'')
SET @Year = isnull(@year, year(getdate())-1)


DECLARE @fk_cli_pkid INT
    ,   @ServerAndDB_for_pfcAppended nvarchar(100)

DECLARE client_set CURSOR FOR
SELECT  DISTINCT mtx.fk_cli_pkid, SettingValue+ ''.dbo.pfc_appended''
FROM    mtx_ComplianceAndEarlyRefill_tracking AS mtx
JOIN    prola7.Invoice_Screens.dbo.client_definition AS def
ON      mtx.fk_cli_pkID = def.fk_cli_pkid
AND     fk_lkSettings_pkID  = 45
AND     RecordStatus = 1 

OPEN    client_set

FETCH next FROM client_set
INTO    @fk_cli_pkid, @ServerAndDB_for_pfcAppended

WHILE   @@FETCH_STATUS = 0 BEGIN

 set @sql = '
INSERT INTO tmp_Aggregate_Compliance_counts (pfc_fk_prv_pkid, RxYear, RxMonth, Compliance)

SELECT  pfc.pfc_fk_prv_pkid
    ,   year(mtx.pfc_dateofservice) AS RxYear
    ,   0 AS RxMonth
    ,   cast(mtx.Compliance as decimal (6,5))
FROM    mtx_ComplianceAndEarlyRefill_tracking AS mtx
LEFT OUTER JOIN @ServerAndDB_for_pfcAppended AS pfc
ON      mtx.pp_clientfile   = pfc.pp_clientfile
AND     mtx.pp_mirror_pkid  = pfc.pp_mirror_pkid
AND     mtx.fk_cli_pkid     = @fk_cli_pkid
'+@JoinFilter+'
WHERE   pfc.pfc_status = 0
AND     year(mtx.pfc_dateofservice) = '+cast(@Year as nvarchar)+'
'+@Criteria+'
GROUP BY pfc.pfc_fk_prv_pkid, year(mtx.pfc_dateofservice)
' print @sql  EXEC sp_executesql @sql


FETCH next FROM client_set
INTO    @fk_cli_pkid, @ServerAndDB_for_pfcAppended

END

CLOSE client_set
DEALLOCATE client_set