我有现有的表，并希望使自动编号成为一个表中的主键，而使另一个表中的外键。 有什么好办法？

Question

In Access, I have one table called courses and another table called lessons

the table courses

id  name    code
1   english LEN
2   german  LDE
3   math    SMA

the table lessons

id  name        coursename  class_id
1   shakespare  english     ?
2   hesse       german      ?
3   trigonometrymath        ?
4   algebra     math        ?
5   whitman     english     ?

Previously I used course name as a primary key in courses and a foreign key in classes. Now I want to use the autonumber field course_id instead. What is a good way to make this transition?

Answer 1

Your question is a little messed up compared to the tables you are presenting. What I understand is you have an autonumber field in courses named id . You want to store that in lessons in a field called course_id . If this is true then follow the following:

The easiest way would be to open the lessons table in design view. Add the course_id field to the table as a long integer and save. Then execute the following query:

UPDATE lessons
INNER JOIN courses ON courses.name = lessons.coursename
SET lessons.course_id = courses.id

Then open the lessons table in design view again and delete the coursename field.