Data comparison between two tables (php + mysql)

Data comparison between two tables (php + mysql) table_aid, code1, xiaoming2, daniu3, sige5, wangqiang6, limingtable_bid, aid1, 6. I want to display the following results, the contents of Table A corresponding to Table B are highlighted. 1: Data comparison between two tables (php + mysql)
Table_a
Id, code
1, xiaoming
2, daniu
3, sige
5, wangqiang
6. liming

Table_ B
Id, aid
1, 2
2, 3
3, 6
The following figure shows the effect. the content of Table A corresponding to Table B is highlighted:
1, xiaoming
2, daniu
3, sige
5, wangqiang
6. liming

Ask experts for solutions.

------ Solution --------------------
Select a. id, a. code, B. aid from a outer join B on a. id = B. id order by a. id asc
Then, you can highlight the value of B. aid.
------ Solution --------------------
The upstairs method is feasible.
------ Solution --------------------
SELECT
A. id, a. code,
(Case when B. id IS NULL THEN 'n' 'else' END) AS IsHight
FROM
A
Left join B ON a. id = B. id
Order by a. id

If the IsHeight value is 'Y', it is highlighted.