sql server while循环+if分支判断+嵌套语句综合

DECLARE @i INT ,@j INT
SET @i=1
set @j=1
WHILE @i<11
    BEGIN
    WHILE @j<20	
			IF (LEN(@i)=1)
				BEGIN 
						IF (LEN(@j)=1)
							BEGIN
								PRINT '00'+CAST(@i AS VARCHAR)+'0'+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
						ELSE
							BEGIN
								PRINT '00'+CAST(@i AS VARCHAR)+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
				END
			ELSE IF (LEN(@i)=2)
				BEGIN 
						IF (LEN(@j)=1)
							BEGIN
								PRINT '0'+CAST(@i AS VARCHAR)+'0'+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
						ELSE
							BEGIN
								PRINT '0'+CAST(@i AS VARCHAR)+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
				END
			ELSE IF (LEN(@i)=3)
				BEGIN 
						IF (LEN(@j)=1)
							BEGIN
								PRINT CAST(@i AS VARCHAR)+'0'+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
						ELSE
							BEGIN
								PRINT CAST(@i AS VARCHAR)+CAST(@j AS VARCHAR)
								set @j=@j+1
							END
				END
			
set @j=1
set @i=@i+1
END