Alter Proc [dbo].[searchnum]  
(@keyword nvarchar(200)
)
as
Begin
    If ( CHARINDEX('|',@keyword)>0)
    Begin
        declare @sql nvarchar(2000)
        Create table #table(col varchar(20))
        set @sql='insert into #table(col) select '+replace(@keyword,'|',' col union all select ')
        Execute(@sql)
        select count(*) from product where EXISTS   (select * from #table)
        Drop table #table 
    End
    Else
    Begin
     select count(*) from product where pname  like '%'+@keyword+'%'    
    End
End

------解决方案--------------------
SQL code

declare @keyword  varchar(max)
set @keyword='儿童|玩具'
with product  as
(
    select '儿童' as pname union all
    select '玩具' union all 
    select '物品' union all
    select '食品'
)
--把查询where条件反写
select * from product where @keyword like '%'+pname+'%'
--pname
-------
--儿童
--玩具

--(2 row(s) affected)