Integrity constraint violation:

Make sure in model to tell it the primary key if not id. Like

protected $primaryKey = 'some_id';
// or
protected $primaryKey = 'whateverid';

You cannot reference a foreign key in the other table if it does not exist.

Your form will allow me to enter 'abc' in the dept_id field but the foreign key constraint says that if you don't have a row in departments with key of 'abc' then you cannot insert the student.

If you want to allow the student to be assigned to a department then you should present this as a drop down list built from the departments table so that only existing values can be selected.

clear?

yes, clear but i am new, can you help me to do it

@Snapey can you help me to do it

Do you have any departments created?

Does your form work ok if you enter the id of one of the existing departments?

yes

show the schema for the departments table

    public function up()
{
    Schema::create('departments', function (Blueprint $table) {
        //   $table->increments('id');
        $table->engine = 'InnoDB';

        $table->string('dept_id');
        $table->string('name');
        $table->timestamps();

        $table->primary('dept_id');
    });
}

In your controller

 $departments = Departments::orderBy('name','ASC')->get();

then pass $departments to your view.

Then on your form, instead of the dept_id text field;

    <select  id="dept_id" name="dept_id">
        <option value="" >Choose Department</option>
        @foreach($departments as $department)
            <option value='{{ $department->id }}'>{{ $department->name }}</option>
        @endforeach
    </select>

@Snapey one last problem, can you solve it for me.... please

one last problem, can you solve it for me.... please

Sorry, my crystal ball is in for repair

crystal ball??

https://en.wikipedia.org/wiki/Crystal_ball

:) sorry... i am talking about my problem

What problem? Can it wait until the crystal ball is polished?

ok.... sure :)

one last problem, can you solve it for me.... please

WHAT LAST PROBLEM ?????? I'm being sarcastic because you have not said... WHAT?

"These credentials do not match our records."

when i am trying to do a login then get this error, and i am sure i enter correct values

i am using default authentication for login, but for registration i am using my own method

    public function addStudent(Request $request)
        {
            $this->validate($request, [
                'roll_no'         => 'required|min:1',
                'name'            => 'required|min:2',
                'father_name'     => 'required|min:3',
                'address'         => 'required|min:3',
                'cnic'            => 'required|min:13',
                'phone_no'        => 'required|min:11',
                'father_phone_no' => 'required|min:11',
                'email'           => 'required|email',
                'password'        => 'required|confirmed|min:6',
                'dept_id'         => 'required|min:1',

            ]);

            $data = array(
                    'roll_no'   => $_POST['roll_no'],
                    'name'      => $_POST['name'],
                    'father_name' => $_POST['father_name'],
                    'address'   => $_POST['address'],
                    'cnic'      => $_POST['cnic'],
                    'phone_no'  => $_POST['phone_no'],
                    'father_phone_no' => $_POST['father_phone_no'],
                    'email'     => $_POST['email'],
                    'password'  => bcrypt('password'),
                    'dept_id'   => $_POST['dept_id'],
                );
                Student::Insert($data);
                return redirect('admin/showStudents');
            }

so nothing to do with integrity constraint violation?

Start a new thread?

if you are using standard Auth, it's not going to validate against an entry in a model called Student

ok i will start a new thread