Level 46
Yep, create another migration.
But, when you're ready to ship, it's not a bad idea to try and rationalise all your migrations.
Jan 3, 2018
8
Level 3
How do I add a foreign key constraint to an already migrated migration?
I want to add a foreign key constraint to my user_id column in my posts table but I'm not sure how I would be able to do that, I read something about doctrine/dbal which can be used to modify columns in your database but it doesn't list anything there about adding foreign key constraints.
I want to add this code to my migration but I'm not sure if the doctrine/dbal ->change() method would work.
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
public function up()
{
Schema::create('posts', function (Blueprint $table) {
$table->increments('id');
$table->integer('user_id');
$table->string('title');
$table->text('content');
$table->string('slug')->nullable();
$table->string('tags')->nullable();
$table->timestamps();
});
}
Am I just better off creating another migration and just adding the foreign constraint to my posts table?
Level 3
@topvillas what do you mean by rationalise? I'm sorry, I'm not a native English speaker, my English vocabulary is somewhat minimal.
Level 46
Look at all the migrations and merge things that should be together.
Like the example you're asking about.
Create a new migration that contains the foreign key but when you're ready to ship, merge it into the posts table migration.
Level 3
@topvillas thanks! one last thing, i'm not quite sure if this creates an actual column or not in my database when i migrate it, so is it still necessary to drop the column on down()?
public function up()
{
Schema::table('posts', function (Blueprint $table) {
//
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
});
}
public function down()
{
Schema::table('posts', function (Blueprint $table) {
//
$table->dropColumn('user_id');
});
}
Level 46
No, it references an existing column.
Level 3
@topvillas thank you so much!
Level 3
@topvillas something went wrong, i am getting this errors when i ran migrate
In Connection.php line 664:
SQLSTATE[HY000]: General error: 1005 Can't create table `test_db`.`#sql-116c_4d1` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `posts` add
constraint `posts_user_id_foreign` foreign key (`user_id`) references `users` (`id`) on delete cascade)
In PDOStatement.php line 107:
SQLSTATE[HY000]: General error: 1005 Can't create table `test_db`.`#sql-116c_4d1` (errno: 150 "Foreign key constraint is incorrectly formed")
In PDOStatement.php line 105:
SQLSTATE[HY000]: General error: 1005 Can't create table `test_db`.`#sql-116c_4d1` (errno: 150 "Foreign key constraint is incorrectly formed")
Level 122
have you posted the same problem 3 times?
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