SQLSTATE[HY000]: General error: 1364 Field 'requisition_id' doesn't have a default value - laravel-5.4

Question

Hi following are my relations.
SubmitApplication.php
public function requisition()
{
return $this->hasMany(Requisition::class);
}
Requisition.php
public function submitApplication()
{
return $this->belongsTo(SubmitApplication::class);
}
My blade
<form class="btn-group" action="{{ route('requisitions.update', ['id' => $requisition->id]) }}" method="post">
{{ method_field('PATCH') }}
{{ csrf_field() }}
<button type="submit" class="btn btn-success btn-xs">تایید</button>
</form>
RequisitionController.php
public function update(Request $request, SubmitApplication $submitApplication)
{
$submitApplication->approved = 1;
$submitApplication->save();
return redirect()->back();
}
For requisitions table:
public function up()
{
Schema::create('requisitions', function (Blueprint $table) {
$table->increments('id');
$table->integer('school_id')->unsigned();
$table->string('type');
$table->string('status');
$table->string('date');
$table->timestamps();
$table->foreign('school_id')->references('id')->on('schools');
});
}
For submit_applications table:
public function up()
{
Schema::create('submit_applications', function (Blueprint $table) {
$table->increments('id');
$table->integer('requisition_id')->unsigned();
$table->integer('school_id')->unsigned();
$table->integer('approved');
$table->string('application');
$table->timestamps();
$table->foreign('requisition_id')->references('id')->on('requisitions');
$table->foreign('school_id')->references('id')->on('schools');
});
}
RequisitionController.php
public function update(Request $request, SubmitApplication $submitApplication)
{
$submitApplication->approved = 1;
$submitApplication->save();
return redirect()->back();
}
I Get this error.
SQLSTATE[HY000]: General error: 1364 Field 'requisition_id' doesn't
have a default value (SQL: insert into submit_applications
(approved, updated_at, created_at) values (1, 2018-06-18
04:22:48, 2018-06-18 04:22:48))
When I click approved button. it added. id do not want add
Maybe am I doing wrong?

Answer 1

In your submit_applications table, set nullable to requisition_id
public function up()
{
Schema::create('submit_applications', function (Blueprint $table) {
$table->increments('id');
$table->integer('requisition_id')->nullable()->unsigned();
$table->integer('school_id')->nullable()->unsigned();
$table->integer('approved')->nullable(true);
$table->string('application')->nullable(true);
$table->timestamps();
$table->foreign('requisition_id')->references('id')->on('requisitions');
$table->foreign('school_id')->references('id')->on('schools');
});
}