一个sql的问题！

[oneal3417]

以下两个sql语句，为什么执行出来的结果完全不一样？

  select a.rq,a.ontime,a.ywy,e.danwbh,e.dwmch,c.spbh,c.spmch,c.dw,c.shpchd,c.shpgg,
       b.djbh,b.pihao,b.jwh,b.shl,
       b.dj,b.je,b.tichml,a.kpman,b.fahuor,b.fuhr,a.username,b.sxrq,a.is_fapiao
  from cwk a(nolock),ywmxk b(nolock),spkfk c(nolock),mchk e(nolock)
  where a.djbh=b.djbh and a.dwbh=e.dwbh and b.spid=c.spid 
      and b.djbh like 'XSA'+'%'
      and a.ywy like '%%'
      and b.chonghdjbh like case when '%%' ='是' then '%' else '' end
      and c.beactive<>'否' 
      and a.rq>='2010-06-01' and a.rq<='2010-06-01' 
      and (e.zjm like '%%' or 
           e.danwbh like '%%' or
           e.dwmch like '%%')
  order by a.djbh,a.rq

第一句执行后返回5044条记录

declare
  @djbh char(25),
  @dwmch char(45),
  @chonghong char(2),
  @ywy char (10),
  @srq char (15),
  @erq char (15)

  set @djbh ='%%'
  set @dwmch ='%%'
  set @chonghong ='%%'
  set @ywy ='%%'
  set @srq ='2010-06-01'
  set @erq ='2010-06-01'


  select a.rq,a.ontime,a.ywy,e.danwbh,e.dwmch,c.spbh,c.spmch,c.dw,c.shpchd,c.shpgg,
       b.djbh,b.pihao,b.jwh,b.shl,
       b.dj,b.je,b.tichml,a.kpman,b.fahuor,b.fuhr,a.username,b.sxrq,a.is_fapiao
  from cwk a(nolock),ywmxk b(nolock),spkfk c(nolock),mchk e(nolock)
  where a.djbh=b.djbh and a.dwbh=e.dwbh and b.spid=c.spid 
      and b.djbh like 'XSA'+'%'
      and a.ywy like @ywy
      and b.chonghdjbh like case when @chonghong ='是' then '%' else '' end
      and c.beactive<>'否' 
      and a.rq>=@srq and a.rq<=@erq 
      and (e.zjm like @dwmch or 
           e.danwbh like @dwmch or
           e.dwmch like @dwmch)
  order by a.djbh,a.rq

第二条返回0条记录。
何解？求解答！谢谢！

[oneal3417]

晕！没有人能回答我吗？

[SQLCenter]

@djbh char(25),
@dwmch char(45),
@chonghong char(2),
@ywy char (10),
@srq char (15),
@erq char (15)
---------------
全部改为 varchar

[SQLCenter]

declare @c char(8), @v varchar(8)
set @c = '%%'
set @v = '%%'
select * from sysobjects where name like @c --> 0记录返回，相当于 like '%%      '
select * from sysobjects where name like @v

[duanzhi1984]

是数据类型惹的祸！

VARCHAR(10)与CHAR(10) 数据库分配的空间是不一样的

[claro]

http://topic.csdn.net/u/20100719/14/a32a3f69-4353-402b-9744-75c762a2e377.html

了解

[csdnadmin]

同意，是数据类型得导致，

[njlywy]

数据类型惹的祸…