我的旁门左道

declare @DBname nvarchar(500) --数据库名
declare @ztname nvarchar(500) --账套名
declare @readonly nvarchar(3) --状态
declare @sql varchar(8000)--SQL语句
declare @sql_tmp varchar(8000)--SQL语句
declare @count_s nvarchar(4000)--返回值

declare @n int
set @n=1
select @sql='select ztname as a0,DBname as name,ztname as a1,ztname as a2,ztname as a3,ztname as a4,ztname as a5,ztname as a6  from K_DBlist where 1=2'
select @sql_tmp='select ztname as a0,DBname as name,ztname as a1,ztname as a2,ztname as a3,ztname as a4,ztname as a5,ztname as a6  from K_DBlist where 1=2'
begin 
 DECLARE mycursor cursor FOR select DBname,ztname,readonly  from K_DBlist where ishide=0
OPEN mycurso
fetch next from mycursor into @DBname,@ztname,@readonly
while @@fetch_status<>-1
 begin
    select @sql=@sql+' UNION ALL '+'select '''+@ztname+''' as a0,'''+@DBname+''' as name,kc.ctypeid,kc.ccode,kc.cname,kc.pricepass,b.pass,b.roleid from ['+@DBname+'].dbo.K_Customer kc left join ['+@DBname+'].dbo.K_Customerpass  b on b.ctypeid=kc.ctypeid where (kc.ccode='''+@user+''' or kc.cname='''+@user+''') and b.pass='''+@pass+''''
    select @sql_tmp=@sql_tmp+' UNION ALL '+'select '''+@ztname+''' as a0,'''+@DBname+'$'+@readonly+''' as name,kc.ctypeid,kc.ccode,kc.cname,kc.pricepass,b.pass,b.roleid from ['+@DBname+'].dbo.K_Customer kc left join ['+@DBname+'].dbo.K_Customerpass  b on b.ctypeid=kc.ctypeid where (kc.ccode='''+@user+''' or kc.cname='''+@user+''') and b.pass='''+@pass+''''   

    fetch next from mycursor into @DBname,@ztname,@readonly
 end
 Close mycurso
 deallocate mycursor 
end 
set @count_s=N'select @count=count(*) from ('+@sql+') as aa';
EXEC sp_executesql @count_s, N'@count int output',@n output;

if @n > 1
    begin        
     exec(@sql_tmp)
    end
else
    begin    
        exec(@sql)
    end