How to compare 2 mysql table with a primary key in

How to compare 2 mysql table with a primary key in

I want to compare 2 table with same primary key. For example:
Table A:
--------
ID, Oder_ID
Table B:
--------
ID, Value SELECT ID, Oder_ID FROM Table A WHERE Oder_ID= $d[1];& want to
find ID from Table A & then want to retrieve data from Table B using ID.
Any suggestion please. Thanks in advance.