where clause in laravel for search - php

Question

I am trying to select rows from table students using laravel query for searching but on searching it's returning all rows from table.
$data = DB::table('students')
->select(['name', 'username'])->where('institute', $inst)
->where('username', 'LIKE', '%'.$search.'%')
->orWhere('name', 'LIKE', '%'.$search.'%')
->orWhere('email', 'LIKE', '%'.$search.'%')
->orWhere('contact', 'LIKE', '%'.$search.'%')
->orderBy('id', 'DESC')
->paginate(10);

Answer 1

This is the thing, at least for what I can see, you have two kind of filters:
Students that are in a given institute
Students that have a similar username, name, email or contact than the given search term
If so, the problem in your query are the orWhere() clauses. Let's simplify your query to illustrate the issue:
$data = DB::table('students')
->where('institute', $inst)
->orWhere('name', 'LIKE', '%'.$search.'%')
->get();
In the above code, the statement will get all the students that have the institute equals to $inst OR have a name similar to %search%. So, the results could include students that are not in the given institute. You see the issue now?
In order to first filter by institute AND get records that have a similar similar username, name, email or contact, you could wrap the second conditions in a closure. Try this:
$data = DB::table('students')
->select(['name', 'username'])
->where('institute', $inst)
->where(function ($query) use ($search) { // <<<
$query->where('username', 'LIKE', '%'.$search.'%')
->orWhere('name', 'LIKE', '%'.$search.'%')
->orWhere('email', 'LIKE', '%'.$search.'%')
->orWhere('contact', 'LIKE', '%'.$search.'%');
})
->orderBy('id', 'DESC')
->paginate(10);