yii2/framework/db/mysql/ColumnSchema.php

<?php
/**
 * @link https://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license https://www.yiiframework.com/license/
 */

namespace yii\db\mysql;

use yii\db\ExpressionInterface;
use yii\db\JsonExpression;

/**
 * Class ColumnSchema for MySQL database
 *
 * @author Dmytro Naumenko <d.naumenko.a@gmail.com>
 * @since 2.0.14.1
 */
class ColumnSchema extends \yii\db\ColumnSchema
{
    /**
     * {@inheritdoc}
     */
    public function dbTypecast($value)
    {
        if ($value === null) {
            return $value;
        }

        if ($value instanceof ExpressionInterface) {
            return $value;
        }

        if ($this->dbType === Schema::TYPE_JSON) {
            return new JsonExpression($value, $this->type);
        }

        return $this->typecast($value);
    }

    /**
     * {@inheritdoc}
     */
    public function phpTypecast($value)
    {
        if ($value === null) {
            return null;
        }

        if ($this->type === Schema::TYPE_JSON) {
            return json_decode($value, true);
        }

        return parent::phpTypecast($value);
    }
}