yiisoft/yii2 · error · yii\base\InvalidCallException

Unable to link models: the primary key of {} is null.

Error message

Unable to link models: the primary key of {} is null.

What it means

Error "Unable to link models: the primary key of {} is null." thrown in yiisoft/yii2.

Source

Thrown at framework/db/BaseActiveRecord.php:1596

                }
            }
        }

        unset($this->_related[$name]);
    }

    /**
     * @param array $link
     * @param ActiveRecordInterface $foreignModel
     * @param ActiveRecordInterface $primaryModel
     * @throws InvalidCallException
     */
    private function bindModels($link, $foreignModel, $primaryModel)
    {
        foreach ($link as $fk => $pk) {
            $value = $primaryModel->$pk;
            if ($value === null) {
                throw new InvalidCallException('Unable to link models: the primary key of ' . get_class($primaryModel) . ' is null.');
            }
            if (is_array($foreignModel->$fk)) { // relation via array valued attribute
                $foreignModel->{$fk}[] = $value;
            } else {
                $foreignModel->{$fk} = $value;
            }
        }
        $foreignModel->save(false);
    }

    /**
     * Returns a value indicating whether the given set of attributes represents the primary key for this model.
     * @param array $keys the set of attributes to check
     * @return bool whether the given set of attributes represents the primary key for this model
     */
    public static function isPrimaryKey($keys)
    {
        $pks = static::primaryKey();

View on GitHub (pinned to 66f00d18a2)

When it happens

Trigger: Thrown at framework/db/BaseActiveRecord.php:1596 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of yiisoft/yii2@66f00d18a2 (2026-08-17). Data as JSON: /api/errors/3c404f4516e81c6e. Report an issue: GitHub.