print 没有结果

下面语句 为什么我print没有结果啊？

DECLARE @WHSCODE VARCHAR(20),@ITEMCODE VARCHAR(30),@Codebars varchar(30),@datefrom datetime,@dateto datetime
SET @DATEFROM='2010-01-01'
SET @DATETO='2011-01-01'
SET @WHSCODE='1-AZJT01'
SET @ITEMCODE='A'
declare @sql nvarchar(4000)
set @sql='s'
declare @cur varchar(4000) --保存动态游标语句，实现物料模糊查询
declare @type nvarchar(4)
set @cur=N'
declare cur1 cursor for --获取型号列值,作为分组依据
select distinct m.型号
from 
(SELECT tt.DocDate,tt.DocEntry, tt.DocNum, tt.Comments,d.ItemCode,d.Quantity,left(T4.[BatchNum],3) AS COLORCODE
,SUBSTRING(T4.[BatchNum],4,2) AS ''型号'',d.WhsCode,tt.U_DJLX,tt.U_JYLX,d.LineTotal,D.ObjType,D.LineNum
FROM dbo.OIGN AS tt 
INNER JOIN dbo.IGN1 AS d ON tt.DocEntry = d.DocEntry AND tt.CurSource = ''C''
inner join ibt1 T4 ON T4.BaseType = D.ObjType AND D.DocEntry=T4.BaseEntry AND D.LineNum=t4.BaseLinNum
where isnull(SUBSTRING(T4.[BatchNum],4,2),'''')<>'''' and tt.docdate between '
+convert(varchar(20),@datefrom,112)+N' and '''+convert(varchar(20),@dateto,112)
+N''') M 
left join OITM p on p.ITEMCODE=m.itemcode  
inner join owhs t5 on M.whscode = t5.whscode
where M.whscode ='+@whscode+N' and M.ItemCode like '''+@itemcode+N'%'''+N'

open cur1 

fetch next from cur1 into '+@type+'
while @@fetch_status=0
begin
set @sql='+@sql+'['+@type+'],'+'
fetch next from cur1 into '+@type+'
end
set @sql=stuff('+@sql+',1,1,'''')
set '+@sql+'=left('+@SQL+',len('+@SQL+')-1)
close cur1
deallocate cur1'

PRINT @cur


为什么我print后没有结果啊？

检查你的查询语句里的连接和条件是否正确.
没有你的表结构和数据,无法作出进一步的判断.

不知道你的数据情况，不知道你的表结构，貌似不好判断

因为你的@type 没有赋值
SQL code

SET @type = ''

你说的对，这里涉及到的变量只要一个没有赋值就会没有结果，但是哪个@type变量我是用在游标中的，不可能赋值的。我的目的是根据过程传入的参数，将参数作为select 的条件（where itemcode=@itemcode 没问题，但是我想用like 就有问题了，where itemcode like @itemcode 是不行的，所以要用动态语句）
将select 语句作为游标取值来源，这样就有问题了。

可以不用动态SQL,可以这样 LIKE '' + @ITEMCODE + '%'
没有表和数据,无法测试.如果有问题自己稍微修改下
SQL code

DECLARE @WHSCODE    VARCHAR(20)
       ,@ITEMCODE   VARCHAR(30)
       ,@Codebars   VARCHAR(30)
       ,@datefrom   DATETIME
       ,@dateto     DATETIME
       ,@SQL        NVARCHAR(4000)
       ,@type       NVARCHAR(4)

SET @DATEFROM='2010-01-01'
SET @DATETO='2011-01-01'
SET @WHSCODE='1-AZJT01'
SET @ITEMCODE='A'
SET @SQL = ''

DECLARE CUR1 CURSOR FOR --获取型号列值,作为分组依据
SELECT DISTINCT M.型号
FROM  
(
    SELECT d.ItemCode
          ,d.WhsCode
          ,SUBSTRING(T4.[BatchNum],4,2) AS '型号'
    FROM dbo.OIGN AS tt  
    INNER JOIN dbo.IGN1 AS d ON tt.DocEntry = d.DocEntry AND tt.CurSource = 'C'
    INNER JOIN ibt1 T4 ON T4.BaseType = D.ObjType AND D.DocEntry=T4.BaseEntry AND D.LineNum=t4.BaseLinNum
    WHERE ISNULL(SUBSTRING(T4.[BatchNum],4,2),'')<>'' AND tt.docdate BETWEEN @DATEFROM AND @DATETO
) M  
LEFT JOIN OITM P on P.ITEMCODE = M.itemcode   
INNER JOIN owhs T5 on M.whscode = T5.whscode
WHERE M.whscode =@WHSCODE 
AND M.ItemCode LIKE '' + @ITEMCODE + '%'

OPEN CUR1
FETCH NEXT FROM CUR1 INTO @type
WHILE @@FETCH_STATUS=0
BEGIN
    SET @sql= @sql + ',[' + @type + ']'
    FETCH NEXT FROM CUR1 INTO @type
END

SET @sql = STUFF(@sql,1,1,'')
CLOSE CUR1
DEALLOCATE CUR1

SELECT @sql

谢谢你的回答，但是现在有个问题，提示传递到 SUBSTRING 函数的长度参数无效。

ALTER PROC TEST3 
@WHSCODE VARCHAR(20),@ITEMCODE VARCHAR(30),@Codebars varchar(30),@datefrom datetime,@dateto datetime
AS 
BEGIN
DECLARE @SQL NVARCHAR(4000)
  ,@type NVARCHAR(4)

DECLARE CUR1 CURSOR FOR --获取型号列值,作为分组依据
SELECT DISTINCT M.型号
FROM  
(
  SELECT TT.DOCDATE,d.ItemCode
  ,d.WhsCode
  ,SUBSTRING(T4.[BatchNum],4,2) AS '型号'
  FROM dbo.OIGN AS tt  
  INNER JOIN dbo.IGN1 AS d ON tt.DocEntry = d.DocEntry AND tt.CurSource = 'C'
  INNER JOIN ibt1 T4 ON T4.BaseType = D.ObjType AND D.DocEntry=T4.BaseEntry AND D.LineNum=t4.BaseLinNum
  WHERE ISNULL(SUBSTRING(T4.[BatchNum],4,2),'')<>'') M  
LEFT JOIN OITM P on P.ITEMCODE = M.itemcode  
INNER JOIN owhs T5 on M.whscode = T5.whscode
WHERE M.whscode =@WHSCODE 
AND M.ItemCode LIKE '' + @ITEMCODE + '%' AND M.docdate BETWEEN @DATEFROM AND @DATETO

OPEN CUR1
FETCH NEXT FROM CUR1 INTO @type
WHILE @@FETCH_STATUS=0
BEGIN
  SET @sql= @sql + ',[' + @type + ']'
  FETCH NEXT FROM CUR1 INTO @type
END

SET @sql = STUFF(@sql,1,1,'')
set @sql=left(@SQL,len(@SQL)-1)
CLOSE CUR1
DEALLOCATE CUR1

PRINT @sql

END
-- exec test '1-ASCK01','A','','2010-01-01','2011-01-31'

我单独执行select distinct M.型号 这个select 是没问题的。

是不是SELECT DISTINCT M.型号 有NULL 值?
加上这个条件 AND M.型号 IS NOT NULL
SQL code

WHERE M.whscode =@WHSCODE  
AND M.ItemCode LIKE '' + @ITEMCODE + '%' AND M.docdate BETWEEN @DATEFROM AND @DATETO
AND M.型号 IS NOT NULL

谢谢，找到原因了，一下午头都大了，看来自己还有很多不懂的啊。