php - MySQL two tables query records with the same field and output a field

Question

user table

single table

As shown in the figure, how to query the same records of user and user in the single table and output the id of the user table and the exam_name field of the user single table

Or how to change this table to make it better

still have a question

If you want to modify the user in the user table, how can the user corresponding to the single table be modified at the same time? I’m a newbie and I don’t understand very well. I hope my friends can help me and teach me. Thank you

Answer 1

select a.id,a.user,b.exam_namc from user as a join single as b on a.user = b.user

Answer 2

No debugging
1,

select u.id, u.user, s.exam_name from user u, single s where u.user = s.user

2,

update user u,single s  set u.user = '值', s.user = '值' where u.user = u.user and u.id = '条件'

Answer 3

To join two tables when selecting, you can check the usage of sql join.