doctrine/orm · error · Exception

Unknown property {key} on class {class}

Error message

Unknown property {key} on class {class}

What it means

Doctrine ORM builds its DiscriminatorColumnMapping value object from a plain mapping array via DiscriminatorColumnMapping::fromMappingArray(), which is what the XML/YAML/PHP mapping drivers and cached metadata feed. After the required 'type', 'fieldName' and 'name' keys are consumed, every remaining key is assigned onto the mapping object using property_exists(); a key that matches no public property of DiscriminatorColumnMapping throws this exception, naming the offending key and class.

Source

Thrown at src/Mapping/DiscriminatorColumnMapping.php:63

     *     options?: array<string, mixed>|null,
     * } $mappingArray
     */
    public static function fromMappingArray(array $mappingArray): self
    {
        $mapping = new self(
            $mappingArray['type'],
            $mappingArray['fieldName'],
            $mappingArray['name'],
        );
        foreach ($mappingArray as $key => $value) {
            if (in_array($key, ['type', 'fieldName', 'name'])) {
                continue;
            }

            if (property_exists($mapping, $key)) {
                $mapping->$key = $value ?? $mapping->$key;
            } else {
                throw new Exception('Unknown property ' . $key . ' on class ' . static::class);
            }
        }

        return $mapping;
    }

    /** @return list<string> */
    public function __sleep(): array
    {
        $serialized = ['type', 'fieldName', 'name'];

        foreach (['length', 'columnDefinition', 'enumType', 'options'] as $stringOrArrayKey) {
            if ($this->$stringOrArrayKey !== null) {
                $serialized[] = $stringOrArrayKey;
            }
        }

        return $serialized;

View on GitHub (pinned to d9b9ff7301)

Solutions

1. Fix or remove the offending key: only type, fieldName, name, length, columnDefinition, enumType and options are accepted on discriminator-column mappings.
2. If the key belongs to a regular field (precision, scale, ...), move it to the <field>/<column> mapping, not the discriminator column.
3. Clear cached metadata (doctrine orm:clear-cache:metadata) so a stale mapping array from an older ORM version is regenerated.

Example fix

// before
DiscriminatorColumnMapping::fromMappingArray([
    'type'      => 'string',
    'fieldName' => 'dtype',
    'name'      => 'discr',
    'lenght'    => 255, // typo: unknown property
]);

// after
DiscriminatorColumnMapping::fromMappingArray([
    'type'      => 'string',
    'fieldName' => 'dtype',
    'name'      => 'discr',
    'length'    => 255,
]);

$allowed = ['type', 'fieldName', 'name', 'length', 'columnDefinition', 'enumType', 'options'];
$unknown = array_diff(array_keys($mappingArray), $allowed);
if ($unknown !== []) {
    throw new InvalidArgumentException('Unsupported discriminator-column keys: ' . implode(', ', $unknown));
}
return DiscriminatorColumnMapping::fromMappingArray($mappingArray);

try { DiscriminatorColumnMapping::fromMappingArray($array); } catch (Exception $e) { throw new MappingConfigurationException('Invalid <discriminator-column> mapping: ' . $e->getMessage(), 0, $e); }

When it happens

Trigger: Calling DiscriminatorColumnMapping::fromMappingArray() (directly or via a mapping driver / metadata factory) with an array containing a key other than type, fieldName, name, length, columnDefinition, enumType, options. Typical offenders: a misspelled key like 'lenght', or a key valid on regular column mappings (precision, scale, unique, nullable) that DiscriminatorColumnMapping does not define.

Common situations: Hand-written XML or YAML <discriminator-column> definitions with misspelled/unsupported attributes; PHP array mappings copied from a #[Column] definition; metadata cached by an older ORM version with different key names; custom mapping drivers that pass extra keys through.

Related errors

• Unrecognized access strategy type [%s]
• If you want to use a "READ_WRITE" cache an implementation of
• Lazy loading proxies require PHP 8.4 or higher.
• The lazy ghost object feature cannot be disabled anymore. Pl
• Rejecting ID collisions in the identity map cannot be disabl

AI-assisted analysis of doctrine/orm@d9b9ff7301 (2026-08-21). Data as JSON: /api/errors/ffac3497734e2ab2. Report an issue: GitHub.