sql循环打印*号长方形

declare @num int set @num=20  --图像数量
declare @row int set @row=13  --打印多少行
declare @i int set @i=0  
declare @j int set @j=0  
declare @k int set @k=0  
declare @ch varchar(1000) set @ch=''   --第一排 最后一排
declare @cc varchar(1000) set @cc='*'  --中间的
while(@j<@row)
begin
    if(@j>=1 and @j<=@row-2 )
    begin
        while(@k<@num)
        begin
            if(@k=@num-2)
                set @cc=@cc+'*';
            else
                set @cc=@cc+' ';
            set @k=@k+1;
        end
        print @cc;
    end     
    while(@i<@num)
    begin
        set @i=@i+1;
        set @ch=@ch+'*';
    end
    if(@j=0)print @ch;
    if(@j=@row-1)print @ch;
    set @j=@j+1;
end