【轉】t-SQL打印楊輝三角

use tempdb;
GO

--我用存儲過程和臨時表來寫，主要是想最後一個select出來結果，而且排成想要的三角想形狀。
--由於BIGINT數據的限制，最多可以顯示67層。
CREATE proc pr_YangHui
@c int
as
/*    SQL實現顯示楊輝三角    */
/* 版本:   1.0              */
/* 作者: Haiwer             */
/* 版權所有                  */
/* 2006.05.10               */
set nocount on
if @c<2 return        --兩層以下就不排了
declare @i int
declare @j int
declare @sql varchar(8000)
declare @sql1 varchar(8000)
declare @sql2 varchar(8000)
create table #(id int IDENTITY(1,1),a50000 bigint)
insert #(a50000) values (1)   --第一層
set @i=2
while @i<=@c
begin
--爲了實現動態層，只好動態修改臨時表結構
set @sql='alter table # add a'+cast(50000+@i-1 as varchar(10))+' bigint,a'+cast(50000-@i+1 as varchar(10))+' bigint' 
exec (@sql)
set @sql1=''
set @sql2=''
set @j=@i-1
while @j>=0
begin
   --這裏判斷有點亂
   if @j=0
    set @sql1=@sql1+',a'+cast(50000-@j as varchar(10))
   else
    set @sql1=@sql1+',a'+cast(50000-@j as varchar(10))+',a'+cast(50000+@j as varchar(10))
   if @j=@i-1
    set @sql2=@sql2+',1,1'
   else
    if @j=0
     set @sql2=@sql2+',a'+cast(50000-@j-1 as varchar(10))+'+a'+cast(50000-@j+1 as varchar(10))
    else
     set @sql2=@sql2+',a'+cast(50000-@j-1 as varchar(10))+'+a'+cast(50000-@j+1 as varchar(10))+',a'+cast(50000+@j-1 as varchar(10))+'+a'+cast(50000+@j+1 as varchar(10))
 
   set @j=@j-2
end
--去掉多餘的逗號
set @sql1=right(@sql1,len(@sql1)-1)
set @sql2=right(@sql2,len(@sql2)-1)
set @sql=cast(@i-1 as varchar(10))
exec('insert #('+@sql1+') select '+@sql2+' from # where id='+@sql)
set @i=@i+1
end

set @i=50000-@c+1
set @j=50000+@c-1
set @sql=''
--去最長的數據，就是爲了節省顯示空間
select @sql1=CAST(len(cast(max(a50000) as varchar(50)))+1 AS VARCHAR(10)) from #
while @i<=@j
begin
set @sql=@sql+',isnull(cast(a'+cast(@i as varchar(10))+' as varchar('+@sql1+')),'''')'
set @i=@i+1
end
exec ('select id'+@sql+' from # order by id')
drop table #

GO
--調用
pr_YangHui 8
--結果
--id                                                                                   
------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
--1                                              1                                
--2                                         1         1                           
--3                                    1         2         1                      
--4                               1         3         3         1                 
--5                          1         4         6         4         1            
--6                     1         5         10        10        5         1       
--7                1         6         15        20        15        6         1  
--8           1         7         21        35        35        21        7         1