如何在动态 sql 语句中使用表变量？

You can't do this because the table variables are out of scope.

You would have to declare the table variable inside the dynamic SQL statement or create temporary tables.

I would suggest you read this excellent article on dynamic SQL.

http://www.sommarskog.se/dynamic_sql.html

I don't think that is possible (though refer to the update below); as far as I know a table variable only exists within the scope that declared it. You can, however, use a temp table (use the create table syntax and prefix your table name with the # symbol), and that will be accessible within both the scope that creates it and the scope of your dynamic statement.

UPDATE: Refer to Martin Smith's answer for how to use a table-valued parameter to pass a table variable in to a dynamic SQL statement. Also note the limitation mentioned: table-valued parameters are read-only.

Your EXEC executes in a different context, therefore it is not aware of any variables that have been declared in your original context. You should be able to use a temp table instead of a table variable as shown in the simple demo below.

create table #t (id int)


declare @value nchar(1)
set @value = N'1'


declare @sql nvarchar(max)
set @sql = N'insert into #t (id) values (' + @value + N')'


exec (@sql)


select * from #t


drop table #t

You don't have to use dynamic SQL

update
R
set
Assoc_Item_1 = CASE WHEN @curr_row = 1 THEN foo.relsku ELSE Assoc_Item_1 END,
Assoc_Item_2 = CASE WHEN @curr_row = 2 THEN foo.relsku ELSE Assoc_Item_2 END,
Assoc_Item_3 = CASE WHEN @curr_row = 3 THEN foo.relsku ELSE Assoc_Item_3 END,
Assoc_Item_4 = CASE WHEN @curr_row = 4 THEN foo.relsku ELSE Assoc_Item_4 END,
Assoc_Item_5 = CASE WHEN @curr_row = 5 THEN foo.relsku ELSE Assoc_Item_5 END,
...
from
(Select relsku From @TSku Where tid = @curr_row1) foo
CROSS JOIN
@RelPro R
Where
R.RowID = @curr_row;

Well, I figured out the way and thought to share with the people out there who might run into the same problem.

Let me start with the problem I had been facing,

I had been trying to execute a Dynamic Sql Statement that used two temporary tables I declared at the top of my stored procedure, but because that dynamic sql statment created a new scope, I couldn't use the temporary tables.

Solution:

I simply changed them to Global Temporary Variables and they worked.

Find my stored procedure underneath.

CREATE PROCEDURE RAFCustom_Room_GetRelatedProducts
-- Add the parameters for the stored procedure here
@PRODUCT_SKU nvarchar(15) = Null

AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON;

IF OBJECT_ID('tempdb..##RelPro', 'U') IS NOT NULL
BEGIN
DROP TABLE ##RelPro
END


Create Table ##RelPro
(
RowID int identity(1,1),
ID int,
Item_Name nvarchar(max),
SKU nvarchar(max),
Vendor nvarchar(max),
Product_Img_180 nvarchar(max),
rpGroup int,
Assoc_Item_1 nvarchar(max),
Assoc_Item_2 nvarchar(max),
Assoc_Item_3 nvarchar(max),
Assoc_Item_4 nvarchar(max),
Assoc_Item_5 nvarchar(max),
Assoc_Item_6 nvarchar(max),
Assoc_Item_7 nvarchar(max),
Assoc_Item_8 nvarchar(max),
Assoc_Item_9 nvarchar(max),
Assoc_Item_10 nvarchar(max)
);


Begin
Insert ##RelPro(ID, Item_Name, SKU, Vendor, Product_Img_180, rpGroup)


Select distinct zp.ProductID, zp.Name, zp.SKU,
(Select m.Name From ZNodeManufacturer m(nolock) Where m.ManufacturerID = zp.ManufacturerID),
'http://s0001.server.com/is/sw11/DG/' +
(Select m.Custom1 From ZNodeManufacturer m(nolock) Where m.ManufacturerID = zp.ManufacturerID) +
'_' + zp.SKU + '_3?$SC_3243$', ep.RoomID
From Product zp(nolock) Inner Join RF_ExtendedProduct ep(nolock) On ep.ProductID = zp.ProductID
Where zp.ActiveInd = 1 And SUBSTRING(zp.SKU, 1, 2) <> 'GC' AND zp.Name <> 'PLATINUM' AND zp.SKU = (Case When @PRODUCT_SKU Is Not Null Then @PRODUCT_SKU Else zp.SKU End)
End


declare @curr_row int = 0,
@tot_rows int= 0,
@sku nvarchar(15) = null;


IF OBJECT_ID('tempdb..##TSku', 'U') IS NOT NULL
BEGIN
DROP TABLE ##TSku
END
Create Table ##TSku (tid int identity(1,1), relsku nvarchar(15));


Select @curr_row = (Select MIN(RowId) From ##RelPro);
Select @tot_rows = (Select MAX(RowId) From ##RelPro);


while @curr_row <= @tot_rows
Begin
select @sku = SKU from ##RelPro where RowID = @curr_row;


truncate table ##TSku;


Insert ##TSku(relsku)
Select distinct top(10) tzp.SKU From Product tzp(nolock) INNER JOIN
[INTRANET].raf_FocusAssociatedItem assoc(nolock) ON assoc.associatedItemID = tzp.SKU
Where (assoc.isActive=1) And (tzp.ActiveInd = 1) AND (assoc.productID = @sku)


declare @curr_row1 int = (Select Min(tid) From ##TSku),
@tot_rows1 int = (Select Max(tid) From ##TSku);


If(@tot_rows1 <> 0)
Begin
While @curr_row1 <= @tot_rows1
Begin
declare @col_name nvarchar(15) = null,
@sqlstat nvarchar(500) = null;
set @col_name =  'Assoc_Item_' + Convert(nvarchar(2), @curr_row1);
set @sqlstat = 'update ##RelPro set ' + @col_name + ' = (Select relsku From ##TSku Where tid = ' + Convert(nvarchar(2), @curr_row1) + ') Where RowID = ' + Convert(nvarchar(2), @curr_row);
Exec(@sqlstat);
set @curr_row1 = @curr_row1 + 1;
End
End
set @curr_row = @curr_row + 1;
End


Select * From ##RelPro;

GO

Using Temp table solves the problem but I ran into issues using Exec so I went with the following solution of using sp_executesql:

Create TABLE #tempJoin ( Old_ID int, New_ID int);


declare @table_name varchar(128);


declare @strSQL nvarchar(3072);


set @table_name = 'Object';


--build sql sting to execute
set @strSQL='INSERT INTO '+@table_name+' SELECT '+@columns+' FROM #tempJoin CJ
Inner Join '+@table_name+' sourceTbl On CJ.Old_ID = sourceTbl.Object_ID'


**exec sp_executesql @strSQL;**

Here is an example of using a dynamic T-SQL query and then extracting the results should you have more than one column of returned values (notice the dynamic table name):

DECLARE
@strSQLMain nvarchar(1000),
@recAPD_number_key char(10),
@Census_sub_code varchar(1),
@recAPD_field_name char(100),
@recAPD_table_name char(100),
@NUMBER_KEY varchar(10),


if object_id('[Permits].[dbo].[myTempAPD_Txt]') is not null


DROP TABLE [Permits].[dbo].[myTempAPD_Txt]


CREATE TABLE [Permits].[dbo].[myTempAPD_Txt]
(
[MyCol1] char(10) NULL,
[MyCol2] char(1) NULL,


)
-- an example of what @strSQLMain is : @strSQLMain = SELECT @recAPD_number_key = [NUMBER_KEY], @Census_sub_code=TEXT_029 FROM APD_TXT0 WHERE Number_Key = '01-7212'
SET @strSQLMain = ('INSERT INTO myTempAPD_Txt SELECT [NUMBER_KEY], '+ rtrim(@recAPD_field_name) +' FROM '+ rtrim(@recAPD_table_name) + ' WHERE Number_Key = '''+ rtrim(@Number_Key) +'''')
EXEC (@strSQLMain)
SELECT @recAPD_number_key = MyCol1, @Census_sub_code = MyCol2 from [Permits].[dbo].[myTempAPD_Txt]


DROP TABLE [Permits].[dbo].[myTempAPD_Txt]

On SQL Server 2008+ it is possible to use Table Valued Parameters to pass in a table variable to a dynamic SQL statement as long as you don't need to update the values in the table itself.

So from the code you posted you could use this approach for @TSku but not for @RelPro

Example syntax below.

CREATE TYPE MyTable AS TABLE
(
Foo int,
Bar int
);
GO




DECLARE @T AS MyTable;


INSERT INTO @T VALUES (1,2), (2,3)


SELECT *,
sys.fn_PhysLocFormatter(%%physloc%%) AS [physloc]
FROM @T


EXEC sp_executesql
N'SELECT *,
sys.fn_PhysLocFormatter(%%physloc%%) AS [physloc]
FROM @T',
N'@T MyTable READONLY',
@T=@T

The physloc column is included just to demonstrate that the table variable referenced in the child scope is definitely the same one as the outer scope rather than a copy.