--select * from tblDJCodeName
alter proc demo_codename_insert
@codetype varchar(20),
@name varchar(20),
@value int output
as 
declare 
@max int, @sort int
begin
	select @max = max(value), @sort = MAX(Sort) from tblDJCodeName where Name = @name
	if isnull(@max, '') <> ''
		select @value = 1 
	else
		[b]select @value = @max*2 [/b] --使用1,2,4,8.. 的設計風格
	if @sort is null 
		select @sort = 1
	else 
		select @sort = @sort + 1
	insert tblDJCodeName(CodeType, Name, Value, Sort, IsDelete) values(@codetype, @name, @value, @sort, 0)
end

--執行
declare @val varchar(10)
exec demo_codename_insert 'com_demo', '測試', @val output
print @val