SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails

Question

I am trying to insert values into my comments table and I am getting a error. Its saying that I can not add or update child row and I have no idea what that means. My schema

Answer 1

In my case , its no problem in SQL commands , but the inputs was not sending as $request , so in php.ini file :

max_input_vars was 1000 by default and I changed it to :

max_input_vars = 2000

then you have to restart web server .