如图中加粗倾斜的这句话

创建函数

if (object_id('fun_add', 'fn') is not null)

drop function fun_add

go

create function fun_add(@num1 int, @num2 int)

returns int

_ with execute as caller_

as

begin
    declare @result int;
    if (@num1 is null)
        set @num1 = 0;
    if (@num2 is null)
        set @num2 = 0;
    set @result = @num1 + @num2;
    return @result;
end

go

https://blog.csdn.net/weixin_33738982/article/details/93440653