Alter Tables in Laravel with change method

Laravel ships in with the awesomeness of Database Migrations which allows you to version control your database. But there are number of events when you are required to change the datatypes or attributes assigned to your table columns inside of your migrations. Well Laravel got you covered, you can achieve it by the change() helper method.

We'll look at some scenarios on how we can utilise this change() method in our database migrations.

Scenario # 01 : Nullable fields

You're required to make a field nullable and didn't want to break your database and previous records. You can simply create a migration for that likeso,

php artisan make:migration add_nullable_constraint_to_my_table --table=my_table

Inside of your migration, you need to rewrite the field you're referring to and add the change method on it with the alterations.

//up 
Schema::table('my_table', function (Blueprint $table) {
 $table->string( 'name' )->nullable()->change();
});

And for the down method, you can do something like this.

//down
Schema::table('my_table', function (Blueprint $table) {
 $table->string('name')->nullable(false)->change();
});

Scenario # 02: Data Length

What if you need to change the data type's length for some field? For instance, we want to increase the field maximum allowed size from 10 to 50. Well change() is here for the rescue.

Its always a good practice for creating separate migrations for these alterations so that it would not conflict.

$table->string( 'name',50 )->change();

Scenario # 03: Change Datatypes

Another scenario is where we need to change the datatype of the field, lets say from string to multiLineString. We can do it with the change method.

Add a new migration and migrate for the changes to take effect.

$table->multiLineString('name')->change();

Bonus Tip

You may call change() method before or after the alteration method you want to apply & it will work the same. For example

$table->string( 'name' )->change()->nullable();

Will work the same as

$table->string( 'address' )->nullable()->change();

Conclusion

If you have any other real world scenarios in mind, let us know in the comments section below & we'll get back to it with the solution. You can also follow us on Twitter.