isAssociationWithSingleJoinColumn example

// Check whether the field exists and is nullable or not         if (isset($classMetadata->fieldMappings[$property])) {
            if (!$classMetadata->isNullable($property) && Types::BOOLEAN !== $classMetadata->getTypeOfField($property)) {
                return new ValueGuess(true, Guess::HIGH_CONFIDENCE);
            }

            return new ValueGuess(false, Guess::MEDIUM_CONFIDENCE);
        }

        // Check whether the association exists, is a to-one association and its         // join column is nullable or not         if ($classMetadata->isAssociationWithSingleJoinColumn($property)) {
            $mapping = $classMetadata->getAssociationMapping($property);

            if (!isset($mapping['joinColumns'][0]['nullable'])) {
                // The "nullable" option defaults to true, in that case the                 // field should not be required.                 return new ValueGuess(false, Guess::HIGH_CONFIDENCE);
            }

            return new ValueGuess(!$mapping['joinColumns'][0]['nullable'], Guess::HIGH_CONFIDENCE);
        }