datatype size in laravelmoigration code example

Example 1: laravel foreign key

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});
OR
Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

Example 2: migration rename column laravel

public function up()
{
    Schema::table('posts', function (Blueprint $table) {
        $table->renameColumn('author_ID', 'user_id');
    });
}