How can I find suitable join keys between two tables if I have more than one same columns Exists in two tables

Question

How can I find suitable join keys between two tables if I have more than one same columns Exists in two tables .in which we need to analyse the tables

Answer 1

You need to identify what are the primary and foreign keys in each table
https://stackoverflow.com/questions/3362225/describe-table-structure

Also it is important if all those tables are properly normalized.. If there is redundant data in the common colums, then a join can produce strange results.
https://www.guru99.com/database-normalization.html

Answer 2

Also keep in mind, that even if two tables have colums with the same name, it doesn't mean that they have the same semantic meaning. For example, you may have a students table and a courses table, and each has an id and a name column, but these are not related to each other. Maybe there is a linking table called participants, where student_id and course_id are connected.

The best way to navigate these connections, is to look at the entity relationship (ER) diagram. That is usually prepared by the person who designs the database.