ZF\Apigility\Admin\Model\DbAutodiscoveryModel::getConstraintForColumn PHP Method

    protected function getConstraintForColumn(Metadata $metadata, $tableName, $columnName)
    {
        /** @var \Zend\Db\Metadata\Object\ConstraintObject $constraint */
        foreach ($metadata->getConstraints($tableName) as $constraint) {
            foreach ($constraint->getColumns() as $column) {
                if ($column == $columnName) {
                    return $constraint;
                }
            }
        }
        return null;
    }