yii\db\mysql\Schema::loadColumnSchema PHP Method

    protected function loadColumnSchema($info)
    {
        $column = $this->createColumnSchema();
        $column->name = $info['field'];
        $column->allowNull = $info['null'] === 'YES';
        $column->isPrimaryKey = strpos($info['key'], 'PRI') !== false;
        $column->autoIncrement = stripos($info['extra'], 'auto_increment') !== false;
        $column->comment = $info['comment'];
        $column->dbType = $info['type'];
        $column->unsigned = stripos($column->dbType, 'unsigned') !== false;
        $column->type = self::TYPE_STRING;
        if (preg_match('/^(\\w+)(?:\\(([^\\)]+)\\))?/', $column->dbType, $matches)) {
            $type = strtolower($matches[1]);
            if (isset($this->typeMap[$type])) {
                $column->type = $this->typeMap[$type];
            }
            if (!empty($matches[2])) {
                if ($type === 'enum') {
                    preg_match_all("/'[^']*'/", $matches[2], $values);
                    foreach ($values[0] as $i => $value) {
                        $values[$i] = trim($value, "'");
                    }
                    $column->enumValues = $values;
                } else {
                    $values = explode(',', $matches[2]);
                    $column->size = $column->precision = (int) $values[0];
                    if (isset($values[1])) {
                        $column->scale = (int) $values[1];
                    }
                    if ($column->size === 1 && $type === 'bit') {
                        $column->type = 'boolean';
                    } elseif ($type === 'bit') {
                        if ($column->size > 32) {
                            $column->type = 'bigint';
                        } elseif ($column->size === 32) {
                            $column->type = 'integer';
                        }
                    }
                }
            }
        }
        $column->phpType = $this->getColumnPhpType($column);
        if (!$column->isPrimaryKey) {
            if ($column->type === 'timestamp' && $info['default'] === 'CURRENT_TIMESTAMP') {
                $column->defaultValue = new Expression('CURRENT_TIMESTAMP');
            } elseif (isset($type) && $type === 'bit') {
                $column->defaultValue = bindec(trim($info['default'], 'b\''));
            } else {
                $column->defaultValue = $column->phpTypecast($info['default']);
            }
        }
        return $column;
    }

 /**
  * @inheritdoc
  * @return ColumnSchema
  */
 protected function loadColumnSchema($info)
 {
     $column = parent::loadColumnSchema($info);
     if (is_object($column)) {
         $column = new ColumnSchema(get_object_vars($column));
     }
     return $column;
 }