title: How to add delete cascade constraint in sql
body: <p>I have 2 tables.Table A have columns as (aid, name,depart) where aid is primary key.</p>
  <p>Table B has (aid1,aid2,aid3,created_by) where aid1 is the primary_key. aid1, aid2 and aid3 all are primary key of Table A</p>
  <p>I want to delete a record in Table B i.e aid1 and simultaneously with delete cascade all three records in TABLE A should be deleted. My doubt here is where should I put the delete cascade constraint. I know that in parent child relationship we need to put delete cascade on the child table so that when parent is deleted, child entities are also deleted but in this scenario I dont understand where I should put delete cascade</p>