Foreign key constraint error when adding through migrating - foreign-keys

Question

I am trying to create a foreign key constraint between my two tables on Laravel 4, User and GP. A user can be associated with many GPs. The foreign key is 'Practice_ID' in the users table, which associates with the ID in the GP table.
public function up()
{
// Creates GP table
Schema::create('gp', function($ta)
{
$ta->bigIncrements('id');
$ta->string('address_1');
$ta->string('address_2');
$ta->string('address_3');
$ta->string('post_code');
$ta->timestamps();
});
// Creates the users table
Schema::create('users', function($table)
{
$table->increments('id');
$table->string('username');
$table->string('email');
$table->string('password');
$table->string('confirmation_code');
$table->boolean('confirmed')->default(false);
$table->bigInteger('practice_id');
$table->foreign('practice_id')->references('id')->on('gp');
$table->timestamps();
});
// Creates password reminders table
Schema::create('password_reminders', function($t)
{
$t->string('email');
$t->string('token');
$t->timestamp('created_at');
});
}
The error I am getting is:
[Exception]
SQLSTATE[HY000]: General error: 1005 Can't create table
'doctor.#sql-3ac_a4' (errno: 150) (SQL: alter table users add
constraint users_practice_id_foreign foreign key (practice_id)
references gp (id)) (Bindings: array (
))

Answer 1

err 150 is most likely a data type mismatch.
delcare the foregin key as an unsigned int in the users table:
$table->integer('practice_id')->unsigned();
Also verify your db engine is INNODB that supports FK constraints