Storing Arrays and JSON Data in a Laravel Database Column

Storing an array or arbitrary structured data in a single database column is a common need — user preferences, a product's variable attributes, a flexible settings blob — and Eloquent's casting system handles the JSON encoding and decoding transparently, so a model attribute behaves as a real PHP array in your code.

Setting up the migration

Schema::table('users', function (Blueprint $table) {
    $table->json('preferences')->nullable();
});

Casting the column to an array

class User extends Model
{
    protected $casts = [
        'preferences' => 'array',
    ];
}

Reading and writing it as a plain PHP array

$user->preferences = ['theme' => 'dark', 'notifications' => true];
$user->save();

// later
$theme = $user->preferences['theme']; // 'dark'

The array cast is what makes this work — without it, $user->preferences would just be the raw JSON string from the database, and you'd need to manually call json_decode()/json_encode() around every read and write.

Updating a single key without overwriting the whole array

$preferences = $user->preferences;
$preferences['theme'] = 'light';
$user->preferences = $preferences;
$user->save();

Assigning directly into a nested array key ($user->preferences['theme'] = 'light') doesn't reliably trigger Eloquent's change tracking — reading the whole array out, modifying it, then reassigning it back (as above) is the safe pattern that ensures the change is actually detected and saved.

Querying inside a JSON column

$darkModeUsers = User::where('preferences->theme', 'dark')->get();

$users = User::whereJsonContains('preferences->tags', 'vip')->get();

The -> syntax in a column name is Eloquent's shorthand for querying into a JSON column's nested keys, translating to the appropriate JSON path syntax for whichever database driver is in use (MySQL, PostgreSQL, and others each have their own underlying JSON query syntax that Eloquent abstracts over).

Using the AsCollection cast for a fluent Collection instead of a plain array

use Illuminate\Database\Eloquent\Casts\AsCollection;

protected $casts = [
    'preferences' => AsCollection::class,
];

$user->preferences->get('theme'); // Collection's fluent API instead of array syntax

Using a custom cast class for a typed object instead of a raw array

class Preferences implements CastsAttributes
{
    public function get($model, $key, $value, $attributes)
    {
        return PreferencesDto::fromArray(json_decode($value, true));
    }

    public function set($model, $key, $value, $attributes)
    {
        return json_encode($value->toArray());
    }
}

For genuinely structured data with known, specific fields (rather than a loose, arbitrary bag of settings), a custom cast returning a proper typed object gives IDE autocomplete and type safety that a plain array cast doesn't — worth the extra setup once the JSON structure is stable and well-defined enough to justify it.

When a JSON column is (and isn't) the right choice

A JSON column suits genuinely flexible, loosely-structured, or infrequently-queried data — for anything needing frequent filtering, indexing, or relational integrity (foreign keys, uniqueness constraints on individual values), normal relational columns or a proper related table remain the better-suited, more queryable design.