I added foreign key to my table, but forgot to make it nullable().
How can I change column now? As I understand I have to create new migration file with --table flag and add something like: ->nullable()->change();
Correct?
Yes, you need to create another migration or you rollback your previous migration.
There is an example on the Laravel page for modifying columns:
Schema::table('users', function (Blueprint $table) {
$table->string('name', 50)->nullable()->change();
});
See also this link
https://laravel.com/docs/5.8/migrations#modifying-columns
If you prefer a rollback see this link.
https://laravel.com/docs/5.8/migrations#rolling-back-migrations
Related
Trying to learn Laravel, i am following a tutorial from laracast called Laravel 8 from scratch and has now reached episiode about cascades
https://laracasts.com/series/laravel-8-from-scratch/episodes/53
I'm not getting any errors but if i add a comment to a post, and then delete the post then my comment stays in the database, while his is removed with the post. I tried deleting the post using laravel, but also using tableplus.
My setup is a bit diffrent from his so i'm wondering if my cascades arent working because of something in my setup.
comment migration
Schema::create('comments', function (Blueprint $table) {
$table->id();
$table->foreignId('post_id')->constrained()->cascadeOnDelete();
$table->foreignId('user_id')->constrained()->cascadeOnDelete();
$table->text('body');
$table->timestamps();
});
Post migration
Schema::create('posts', function (Blueprint $table) {
$table->id();
$table->foreignId('user_id');
$table->foreignId('category_id');
$table->string('slug')->unique();
$table->string('title');
$table->text('excerpt');
$table->text('body');
$table->timestamps();
$table->timestamp('published_at')->nullable();
});
I've also tried using $table->foreignKey('post_id')->references('id')->on('posts')->onDelete('cascade) but i cant seem to get it working.
I have also tried adding the constrain my self at the mySql database using
alter table
`comments`
add
constraint `comments_post_id_foreign` foreign key (`post_id`) references `posts` (`id`) on
delete cascade
Do i need a specific use, or could it be my setup?
php/database setup versions from wamp
I think if you search for myisam and innodb, you will probably find the answer.
in myisam, foreign keys are not deleted
When I have tables with relationship (parent and child table) can I migrate them together at once or I need to migrate the child first?
You can't migrate two tables at once, the code won't run in parallel processing
And migrating the child first will cause an error
Illuminate\Database\QueryException : SQLSTATE[HY000]: General error: 1005 Can't create table database.child (errno: 150 "Foreign key constraint is incorrectly formed")
So you have to migrate the parent first
For example, imagine a User has a Pet (domestic animal)
We would have users table and a pets table setup
Schema::create('pets', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('user_id');
$table->foreign('user_id')->references('id')->on('users');
$table->timestamps();
});
If the filename for the pets migration is
2013_11_06_151235_create_pets_table.php
And the filename for the users migration is
2014_10_12_000000_create_users_table.php
You would get the error above, so you have to rename the pets table migration file to a date later than the one of users
for example
2015_11_06_151235_create_pets_table.php
Because Laravel will try to create a database table with a column referencing a column in a table that doesn't exist yet
Hope this helps
If you don't have foreign key constraints, then you can migrate in any order. If you do have a Foreign Key (FK) however, then it depends on your scheme, also then you could benefit from specifying ON UPDATE and ON DELETE rules to your tables. See the mysql docs for that.
I'm working with Laravel 5.6 and Heroku with Postgres database.
I have uploaded my application to Heroku, the login form shows it to me correctly.
The problem comes when doing the migration of the tables with:
heroku run php artisan migrate and using Postgres of Heroku, I made all the configuration correctly but when doing migrate this happens:
In Connection.php line 664:
SQLSTATE[42830]: Invalid foreign key: 7 ERROR: there is no unique
constraint matching given keys for referenced ta ble "users" (SQL:
alter table "sales" add constraint "sales_user_id_foreign" foreign key
("user_id") references "us ers" ("id"))
In Connection.php line 458:
SQLSTATE[42830]: Invalid foreign key: 7 ERROR: there is no unique
constraint matching given keys for referenced ta ble "users"
The strange thing is that the same migration locally does not cause me any problems (MySQL) but Heroku with Postgres show the error.
These are my User and Sales migrations:
Users:
public function up()
{
Schema::create('users', function (Blueprint $table) {
$table->integer('id')->unsigned();
$table->foreign('id')->references('id')->on('people')->onDelete('cascade');
$table->string('user')->unique();
$table->string('password');
$table->boolean('state')->default(1);
$table->integer('idRole')->unsigned();
$table->foreign('idRole')->references('id')->on('roles');
$table->rememberToken();
//$table->timestamps();
});
}
Sales:
public function up()
{
Schema::create('sales', function (Blueprint $table) {
$table->increments('id');
$table->integer('client_id')->unsigned();
$table->foreign('client_id')->references('id')->on('people');
$table->unsignedInteger('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('users');
$table->dateTime('date_time');
$table->decimal('total', 11, 2);
$table->string('status', 20);
$table->timestamps();
});
}
I do not know why I have this error in Heroku but everything works locally. How can I fix this?
It's because the id column on the table users does not have the unique constraint.
You can set the id column as auto-increment and run the migration again:
Users
public function up()
{
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
// Other codes
});
}
The strange thing is that the same migration locally does not cause me any problems (MySQL) but Heroku with Postgres show the error.
It's always a good idea to use the same database software in development and production. MySQL and PostgreSQL aren't drop-in replacements for each other, even with an ORM and a schema migration tool. There are definitely situations where one will be happy and the other won't.
I suspect that if you use MySQL on Heroku your issue will disappear. Heroku doesn't provide MySQL itself, but there are a couple of addons that you could use. JawsDB and ClearDB are both popular options, or if you prefer you could host your own MySQL database on something like RDS.
You could also switch to Postgres locally and see if you can reproduce the error.
Suppose I have a table named "foo" with data and also contains foreign key. Now I want to create a column named "description" in this table. Without reset or rollback how to migrate this table?? Because If I reset or rollback the table then all data will be lost.
As per the docs, you just need to create a separate migration to create the new column.
Create the migration
php artisan make:migration add_description_to_foo
Then just set the migration up with the details you want to add, e.g:
Schema::table('foo', function ($table) {
$table->text('description');
});
Then you can just migrate it:
php artisan migrate
This will allow you to add a column without resetting or rolling back your tables, and thus prevent you from losing your data.
Let's start with your schema. Your table name is foo. You want to add a description column to your foo table without losing existing data. You need to create a new migration for this change.
php artisan make:migration add_columns_to_foo_table --table=foo
A new migration file will be created in your migrations directory. Open it and change it like this:
Schema::table('foo', function ($table) {
$table->text('description');
});
Save it and then run
php artisan migrate
description column will be created immediately without losing your old data as last column. In case you want to reposition your description column you need to use after (in case of MySQL) like this:
Schema::table('foo', function ($table) {
$table->text('description')->after('another_column');
});
Hope you got it.
You will find more details here: https://laravel.com/docs/5.3/migrations#creating-columns
Using artisan migrate command, i am trying to create the table. users table is created but not the columns. What could I check ?
use Illuminate\Database\Migrations\Migration;
class CreateUsersTable extends Migration {
public function up()
{
Schema::create('users', function($table)
{
$table->increments('id');
$table->string('email');
$table->string('password');
$table->timestamps();
});
}
Upon running the above migration file, the table and its columns are successfully created in the database. If you see that the users table is created but not the columns in it, then you might not be looking properly.
I am writing the following answer on my assumption that you're very new to web development also and might not be acquainted with the tools yet.
I assume you're using phpMyAdmin to view your database. If you go to your database and then the users table, you'll be in the Browse tab. Of course, it will be empty because there are no data inserted in the users table, but if you click the Structure tab, then you can view the schema of your users table and see that the columns are created.