如何从mdb的表中检索最后一个主要ID？

Question

I got table with next columns: Id, Name, Age, Class

I am trying to insert new row in db like this:

INSERT INTO MyTable (Name, Age, Class)
VALUES (@name, @age, @class)

And get an exeption:

"Index or primary key cannot contain a Null value."

The question is how to add a new row without knowing next primary Id, or maybe there is a way to get this Id from the table with the help of another query ?

Answer 1

您可以将“ ID”列的数据类型更改为“自动编号”，而不是“整数”。

Answer 2

不确定Access，但MySQL语法为：

INSERT INTO MyTable (Id, Name, Age, Class) VALUES (NULL, @name, @age, @class);

Answer 3

try this

INSERT INTO MyTable (id,Name, Age, Class)
 VALUES ((select max(id)+1 from MyTable),@name, @age, @class)

Answer 4

Please make the "id" column as Auto number in the Mytable and then try

OR else

INSERT INTO MyTable (id,Name, Age, Class)
select max(id)+1,@name, @age, @class FROM MyTable