Search query condition not working - Laravel 5.7 - php

Question

I have this in my view:
<div class="container">
<div class="row">
<div class="col-lg-12 col-md-12">
<form class="search-form search-form-basic" action="/candidates/index" method="post">
{{ csrf_field() }}
<div class="form-row">
<div class="col-md-4 form-group">
<label for="search_email">First name:</label>
<input type="text" name="search_first_name" id="search_first_name" class="form-control" #if(isset(Session::get('inputs')['search_first_name'])) value="{{ Session::get('inputs')['search_first_name'] }}" #endif>
</div>
<div class="col-md-4 form-group">
<label for="search_last_name">Last name:</label>
<input type="text" name="search_last_name" id="search_last_name" class="form-control" #if(isset(Session::get('inputs')['search_last_name'])) value="{{ Session::get('inputs')['search_last_name'] }}" #endif>
</div>
<div class="col-md-4 form-group">
<label for="search_round_number">Round Number:</label>
<input type="text" name="search_round_number" id="search_round_number" class="form-control" placeholder="" #if(isset(Session::get('inputs')['search_round_number'])) value="{{ Session::get('inputs')['search_round_number'] }}" #endif>
</div>
<div class="col-md-4 form-group">
<label for="search_location">location:</label>
<input type="text" name="search_location" id="search_location" class="form-control"
#if(isset(Session::get('inputs')['search_location'])) value="{{ Session::get('inputs')['search_location'] }}" #endif>
</div>
<select name="options" class="col-md-4 form-group">
<option value="">--- Select From ---</option>
<option value="birth_date">Birth Date</option>
<option value="CV_grade_date">CV Grade Date</option>
<option value="source">Source</option>
<option value="recommendation">Recommended</option>
<option value="created_at">Applied</option>
</select>
<div class="col-md-4 form-group">
<label for="search_from_date">From:</label>
<input type="date" name="search_from_date" id="search_from_date" class="form-control"
#if(isset(Session::get('inputs')['search_from_date'])) value="{{ Session::get('inputs')['search_from_date'] }}" #endif>
</div>
<div class="col-md-4 form-group">
<label for="search_to_date">To:</label>
<input type="date" name="search_to_date" id="search_to_date" class="form-control"
#if(isset(Session::get('inputs')['search_to_date'])) value="{{ Session::get('inputs')['search_to_date'] }}" #endif>
</div>
</div>
<div class="form-row">
<div class="col-md-12 col-lg-12">
<button type="submit" class="btn btn-custom"><i class="fa fa-search" aria-hidden="true"></i>Search</button>
<i class="fa fa-times-circle" aria-hidden="true"></i>Clear
</div>
</div>
</form>
</div>
My controller:
public function index(Request $request) {
if($request->isMethod('post')){
$search_first_name = $request->search_first_name;
$search_last_name = $request->search_last_name;
$search_email = $request->search_email;
$search_round_number = $request->search_round_number;
$search_location = $request->search_location;
$search_from_date = $request->search_from_date;
$search_to_date = $request->search_to_date;
$options = Input::get('options');
$recOrSource = null;
if($options == 'recommendation' || $options == 'source') {
$recOrSource = Input::get('options');
$options == null;
}
$candidate = DB::table('candidates')
->when($search_first_name, function ($query) use ($search_first_name) {
return $query->where('first_name', 'like', '%' . $search_first_name . '%');
})
->when($search_last_name, function ($query) use ($search_last_name) {
return $query->where('last_name', 'like', '%' . $search_last_name . '%');
})
->when($search_email, function ($query) use ($search_email) {
return $query->where('email', $search_email);
})
->when($search_round_number, function ($query) use ($search_round_number) {
return $query->where('round_number', $search_round_number);
})
->when($search_location, function ($query) use ($search_location) {
return $query->where('location', $search_location);
})
->when($recOrSource, function ($query) use ($recOrSource,$search_from_date,$search_to_date) {
return $query->where(!empty($recOrSource))->whereBetween('created_at', array($search_from_date, $search_to_date));
})
->when($options, function ($query) use ($options,$search_from_date,$search_to_date ) {
return $query->whereBetween($options, array($search_from_date, $search_to_date));
})
->orderBy('first_name', 'asc')
->orderBy('last_name', 'asc')
->get();
Session::flash('inputs', [
'search_first_name' => $search_first_name,
'search_last_name' => $search_last_name,
'search_email' => $search_email,
'search_round_number' => $search_round_number,
'search_from_date' => $search_from_date,
'search_to_date' => $search_to_date,
'search_location' => $search_location
]);
}else{
Session::forget('inputs');
$candidate = Candidate::orderBy('first_name', 'asc')
->orderBy('last_name', 'asc')
->get();
}
return view('/candidates/index', [
'candidate' => $candidate
]);
When I select "source" as one of the options, and enter from-to dates, I'm receiving this error:
Column not found: 1054 Unknown column '1' in 'where clause' (SQL: select * from candidates where 1 is null and created_at between 2015-8-8 and 2019-1-1 and source between 2015-8-8 and 2019-1-1 order by first_name asc, last_name asc)
However, dd($recOrSource) is returning correct value; I don't see where this "1" is coming from, and why this part is run
->when($options, function ($query) use ($options,$search_from_date,$search_to_date ) {
return $query->whereBetween($options, array($search_from_date, $search_to_date));
})
when I have
if($options == 'recommendation' || $options == 'source') {
$recOrSource = Input::get('options');
$options == null;
}