foreign key laravel migration

1$table->unsignedBigInteger('user_id');
2$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

1Schema::table('posts', function (Blueprint $table) {
2    $table->unsignedBigInteger('user_id');
3
4    $table->foreign('user_id')->references('id')->on('users');
5});
6OR
7Schema::table('posts', function (Blueprint $table) {
8    $table->foreignId('user_id')->constrained();
9});

1$table->foreign('column_name')->references('id')->on('table_name')->onDelete('cascade');

1Schema::table('posts', function (Blueprint $table) {
2    $table->unsignedBigInteger('user_id');
3
4    $table->foreign('user_id')->references('id')->on('users');
5});

1$table->string('foo')->nullable(false)->change();

1use Illuminate\Database\Schema\Blueprint;
2use Illuminate\Support\Facades\Schema;
3
4Schema::table('posts', function (Blueprint $table) {
5    $table->unsignedBigInteger('user_id');
6
7    $table->foreign('user_id')->references('id')->on('users');
8});