Error while migrating in Laravel database on heroku - postgresql

Question

When running heroku run php artisan migrate I get this error, I want to host my app on heroku
In Connection.php line 712
SQLSTATE[42804]: Datatype mismatch: 7 ERROR: column "price" cannot be cast automatically to type numeric
HINT: You might need to specify "USING price::numeric(15,2)". (SQL: ALTER TABLE purchases ALTER price TYPE NUMERIC
(15, 2))
In Connection.php line 501:
SQLSTATE[42804]: Datatype mismatch: 7 ERROR: column "price" cannot be cast automatically to type numeric
HINT: You might need to specify "USING price::numeric(15,2)".
purchase table
lass ChangePurchasePriceDataTyp extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::table('purchases', function (Blueprint $table) {
$table->numeric('price',15,2)->unsigned()->default(0)->change();
});
}
/**
* Reverse the migrations.
*
* #return void
*/
public function down()
{
Schema::table('purchases', function (Blueprint $table) {
//
});
}
}
database.php
'pgsql' => [
'driver' => 'pgsql',
'url' => env('DATABASE_URL'),
'host' => isset($DATABASE_URL['host']) ? $DATABASE_URL['host'] : null,
'port' => isset($DATABASE_URL['port']) ? $DATABASE_URL['port'] : null,
'database' => isset($DATABASE_URL['path']) ? ltrim($DATABASE_URL['path'], "/") : null,
'username' => isset($DATABASE_URL['user']) ? $DATABASE_URL['user'] : null,
'password' => isset($DATABASE_URL['pass']) ? $DATABASE_URL['pass'] : null,
'charset' => 'utf8',
'prefix' => '',
'prefix_indexes' => true,
'schema' => 'public',
'sslmode' => 'prefer',
],
what could be wrong? initial the datatype was decimal but I changed it to numeric