diff --git a/src/App/Action/Person/DeleteAction.php b/src/App/Action/Person/DeleteAction.php
index 8ae3a48..42cc1de 100644
--- a/src/App/Action/Person/DeleteAction.php
+++ b/src/App/Action/Person/DeleteAction.php
@@ -3,6 +3,8 @@
 namespace App\Action\Person;
 
 use App\Service\EntityServiceInterface;
+use Doctrine\ORM\EntityNotFoundException;
+use Doctrine\ORM\ORMInvalidArgumentException;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Zend\Diactoros\Response\JsonResponse;
@@ -24,14 +26,22 @@ class DeleteAction
     {
         $id = $request->getAttribute('id');
 
-        $result = $this->entityService->delete($id);
+        try {
+            $this->entityService->delete($id);
+        } catch (EntityNotFoundException $exception) {
+            $ret = new JsonResponse([
+                'message' => $exception->getMessage(),
+            ]);
 
-        $return = new JsonResponse($result);
+            return $ret->withStatus(404, sprintf('Entity with id `%s` not found.', $id));
+        } catch (ORMInvalidArgumentException $exception) {
+            $res = new JsonResponse([
+                'message' => $exception->getMessage(),
+            ]);
 
-        if (false === $result) {
-            return $return->withStatus(500, 'Failed to delete record.');
+            return $res->withStatus(500, 'Failed to delete record.');
         }
 
-        return $return;
+        return new JsonResponse(true);
     }
 }
diff --git a/src/App/Action/Person/DeleteFactory.php b/src/App/Action/Person/DeleteFactory.php
index f1fe05a..ecaf2ed 100644
--- a/src/App/Action/Person/DeleteFactory.php
+++ b/src/App/Action/Person/DeleteFactory.php
@@ -2,8 +2,8 @@
 
 namespace App\Action\Person;
 
-use App\Action\Article\DeleteAction;
-use App\Service\Article\PersonService;
+use App\Action\Person\DeleteAction;
+use App\Service\Person\PersonService;
 use Interop\Container\ContainerInterface;
 
 class DeleteFactory
diff --git a/src/App/Action/Person/GetAction.php b/src/App/Action/Person/GetAction.php
index 8443529..8ddc314 100644
--- a/src/App/Action/Person/GetAction.php
+++ b/src/App/Action/Person/GetAction.php
@@ -3,6 +3,8 @@
 namespace App\Action\Person;
 
 use App\Service\EntityServiceInterface;
+use Doctrine\ORM\NonUniqueResultException;
+use Doctrine\ORM\NoResultException;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Zend\Diactoros\Response\JsonResponse;
@@ -22,12 +24,21 @@ class GetAction
 
     public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next = null)
     {
-        $id     = $request->getAttribute('id');
-        $entity = $this->entityService->get($id);
+        $id = $request->getAttribute('id');
+        try {
+            $entity = $this->entityService->get($id);
+        } catch (NoResultException $ex) {
+            $ret = new JsonResponse([
+                'message' => $ex->getMessage(),
+            ]);
 
-        if (null === $entity) {
-            $ret = new JsonResponse(false);
-            return $ret->withStatus(404);
+            return $ret->withStatus(404, sprintf('Entity with id `%s` not found.', $id));
+        } catch (NonUniqueResultException $ex) {
+            $ret = new JsonResponse([
+                'message' => $ex->getMessage(),
+            ]);
+
+            return $ret->withStatus(500, 'Duplicate key in database.');
         }
 
         return new JsonResponse($entity);
diff --git a/src/App/Action/Person/PostAction.php b/src/App/Action/Person/PostAction.php
index 7a91f3d..7231940 100644
--- a/src/App/Action/Person/PostAction.php
+++ b/src/App/Action/Person/PostAction.php
@@ -4,6 +4,7 @@ namespace App\Action\Person;
 
 use App\Action\AbstractFormAction;
 use App\Service\EntityServiceInterface;
+use Doctrine\DBAL\Exception\NotNullConstraintViolationException;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Zend\Diactoros\Response\JsonResponse;
@@ -25,11 +26,13 @@ class PostAction extends AbstractFormAction
     {
         $data = $this->getRequestData($request);
 
-        $result = $this->entityService->create($data);
-
-        if (false === $result) {
-            $result = new JsonResponse(false);
-            return $result->withStatus(500, 'Failed to insert record.');
+        try {
+            $result = $this->entityService->create($data);
+        } catch (NotNullConstraintViolationException $exception) {
+            $res = new JsonResponse([
+                'message' => $exception->getMessage(),
+            ]);
+            return $res->withStatus(500, 'Failed to insert record. A required field was not set.');
         }
 
         return new JsonResponse($result);
diff --git a/src/App/Action/Person/PutAction.php b/src/App/Action/Person/PutAction.php
index de6873c..423d63e 100644
--- a/src/App/Action/Person/PutAction.php
+++ b/src/App/Action/Person/PutAction.php
@@ -4,6 +4,7 @@ namespace App\Action\Person;
 
 use App\Action\AbstractFormAction;
 use App\Service\EntityServiceInterface;
+use Doctrine\ORM\EntityNotFoundException;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Zend\Diactoros\Response\JsonResponse;
@@ -26,11 +27,13 @@ class PutAction extends AbstractFormAction
         $id   = $request->getAttribute('id', false);
         $data = $this->getRequestData($request);
 
-        $result = $this->entityService->modify($id, $data);
-
-        if (false === $result) {
-            $result = new JsonResponse(false);
-            return $result->withStatus(500, 'Failed to update record.');
+        try {
+            $result = $this->entityService->modify($id, $data);
+        } catch (EntityNotFoundException $exception) {
+            $res = new JsonResponse([
+                'message' => $exception->getMessage(),
+            ]);
+            return $res->withStatus(404, sprintf('Failed to update record with id `%s`', $id));
         }
 
         return new JsonResponse($result);
diff --git a/src/App/Entity/Person.php b/src/App/Entity/Person.php
index 576c77d..fa04d4b 100644
--- a/src/App/Entity/Person.php
+++ b/src/App/Entity/Person.php
@@ -2,7 +2,7 @@
 
 namespace App\Entity;
 
-use Doctrine\Common\Collections\ArrayCollection;
+use DateTime;
 use Doctrine\ORM\Mapping as ORM;
 use JsonSerializable;
 
@@ -36,7 +36,7 @@ class Person implements JsonSerializable
     private $firstName;
 
     /**
-     * @ORM\Column(name="middle_name", type="string", length=150)
+     * @ORM\Column(name="middle_name", type="string", length=150, nullable=true)
      * @var string
      */
     private $middleName;
@@ -54,43 +54,43 @@ class Person implements JsonSerializable
     private $gender;
 
     /**
-     * @ORM\Column(name="date_of_birth", type="date", nullable=false)
+     * @ORM\Column(name="date_of_birth", type="date", nullable=true)
      * @var string
      */
     private $dateOfBirth;
 
     /**
-     * @ORM\Column(name="place_of_birth", type="string", length=150, nullable=false)
+     * @ORM\Column(name="place_of_birth", type="string", length=150, nullable=true)
      * @var string
      */
     private $placeOfBirth;
 
     /**
-     * @ORM\Column(name="primary_language", type="string", length=150)
+     * @ORM\Column(name="primary_language", type="string", length=150, nullable=true)
      * @var string
      */
     private $primaryLanguage;
 
     /**
-     * @ORM\Column(name="address", type="string", length=255)
+     * @ORM\Column(name="address", type="string", length=255, nullable=true)
      * @var string
      */
     private $address;
 
     /**
      * @ORM\ManyToOne(targetEntity="Person")
-     * @ORM\JoinColumn(name="mother_id", referencedColumnName="id")
+     * @ORM\JoinColumn(name="mother_id", referencedColumnName="id", nullable=true)
      */
     private $mother;
 
     /**
      * @ORM\ManyToOne(targetEntity="Person")
-     * @ORM\JoinColumn(name="father_id", referencedColumnName="id")
+     * @ORM\JoinColumn(name="father_id", referencedColumnName="id", nullable=true)
      */
     private $father;
 
     /**
-     * @ORM\Column(name="email", type="string", length=150)
+     * @ORM\Column(name="email", type="string", length=150, nullable=true)
      * @var string
      */
     private $email;
@@ -159,7 +159,7 @@ class Person implements JsonSerializable
     }
 
     /**
-     * @return datetime
+     * @return DateTime
      */
     public function getDateOfBirth()
     {
@@ -224,7 +224,7 @@ class Person implements JsonSerializable
 
     /**
      * @param int $id
-     * @return User
+     * @return Person
      */
     public function setId(int $id)
     {
@@ -234,7 +234,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $personId
-     * @return User
+     * @return Person
      */
     public function setPersonId(string $personId)
     {
@@ -244,7 +244,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $firstName
-     * @return User
+     * @return Person
      */
     public function setFirstName(string $firstName)
     {
@@ -254,7 +254,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $middleName
-     * @return User
+     * @return Person
      */
     public function setMiddleName(string $middleName)
     {
@@ -264,7 +264,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $lastName
-     * @return User
+     * @return Person
      */
     public function setLastName(string $lastName)
     {
@@ -274,7 +274,7 @@ class Person implements JsonSerializable
 
     /**
      * @param int $gender
-     * @return User
+     * @return Person
      */
     public function setGender(int $gender)
     {
@@ -284,9 +284,9 @@ class Person implements JsonSerializable
 
     /**
      * @param datetime $dateOfBirth
-     * @return User
+     * @return Person
      */
-    public function setDateOfBirth(datetime $dateOfBirth)
+    public function setDateOfBirth(DateTime $dateOfBirth)
     {
         $this->dateOfBirth = $dateOfBirth;
         return $this;
@@ -294,7 +294,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $placeOfBirth
-     * @return User
+     * @return Person
      */
     public function setPlaceOfBirth(string $placeOfBirth)
     {
@@ -304,7 +304,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $primaryLanguage
-     * @return User
+     * @return Person
      */
     public function setPrimaryLanguage(string $primaryLanguage)
     {
@@ -314,7 +314,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $address
-     * @return User
+     * @return Person
      */
     public function setAddress(string $address)
     {
@@ -324,7 +324,7 @@ class Person implements JsonSerializable
 
     /**
      * @param Person $mother
-     * @return User
+     * @return Person
      */
     public function setMother(Person $mother)
     {
@@ -334,7 +334,7 @@ class Person implements JsonSerializable
 
     /**
      * @param Person $father
-     * @return User
+     * @return Person
      */
     public function setFather(Person $father)
     {
@@ -344,7 +344,7 @@ class Person implements JsonSerializable
 
     /**
      * @param string $email
-     * @return User
+     * @return Person
      */
     public function setEmail(string $email)
     {
@@ -354,7 +354,7 @@ class Person implements JsonSerializable
 
     /**
      * @param bool $active
-     * @return User
+     * @return Person
      */
     public function setActive(bool $active)
     {
diff --git a/src/App/Service/Person/PersonService.php b/src/App/Service/Person/PersonService.php
index f47dadd..0780f9a 100644
--- a/src/App/Service/Person/PersonService.php
+++ b/src/App/Service/Person/PersonService.php
@@ -5,9 +5,13 @@ namespace App\Service\Person;
 use App\Entity\Person;
 use App\Hydrator\DoctrineObject;
 use App\Service\EntityServiceInterface;
+use Doctrine\DBAL\Exception\NotNullConstraintViolationException;
 use Doctrine\ORM\EntityManager;
+use Doctrine\ORM\EntityNotFoundException;
+use Doctrine\ORM\NonUniqueResultException;
+use Doctrine\ORM\NoResultException;
+use Doctrine\ORM\ORMInvalidArgumentException;
 use Doctrine\ORM\Query;
-use Exception;
 
 class PersonService implements EntityServiceInterface
 {
@@ -22,12 +26,20 @@ class PersonService implements EntityServiceInterface
      */
     private $hydrator;
 
+    /**
+     * @param EntityManager $em
+     * @param DoctrineObject $hydrator
+     */
     public function __construct(EntityManager $em, DoctrineObject $hydrator)
     {
         $this->em       = $em;
         $this->hydrator = $hydrator;
     }
 
+    /**
+     * 
+     * @return mixed[]
+     */
     public function getList()
     {
         $qb       = $this->em->createQueryBuilder();
@@ -38,6 +50,13 @@ class PersonService implements EntityServiceInterface
         return $entities;
     }
 
+    /**
+     * 
+     * @param int $id
+     * @return mixed
+     * @throws NonUniqueResultException
+     * @throws NoResultException
+     */
     public function get($id)
     {
         $qb = $this->em->createQueryBuilder();
@@ -47,27 +66,36 @@ class PersonService implements EntityServiceInterface
             ->where('p.id = :id')
             ->setParameter('id', $id)
             ->getQuery()
-            ->getOneOrNullResult(Query::HYDRATE_ARRAY);
+            ->getSingleResult(Query::HYDRATE_ARRAY);
 
         return $entity;
     }
 
+    /**
+     * 
+     * @param type $data
+     * @return type
+     * @throws NotNullConstraintViolationException
+     */
     public function create($data)
     {
         $entity = $this->hydrator->hydrate($data, new Person());
-        try {
-            $this->em->persist($entity);
-            $this->em->flush();
-        } catch (Exception $ex) {
-            return false;
-        }
+        $this->em->persist($entity);
+        $this->em->flush();
         return $entity;
     }
 
+    /**
+     * 
+     * @param int $id
+     * @param mixed $data
+     * @return Person
+     * @throws EntityNotFoundException
+     */
     public function modify($id, $data)
     {
         if (null === ($entity = $this->em->find(Person::class, $id))) {
-            return false;
+            throw new EntityNotFoundException('No result was found for query although at least one row was expected.');
         }
 
         $entity = $this->hydrator->hydrate($data, $entity);
@@ -77,18 +105,21 @@ class PersonService implements EntityServiceInterface
         return $entity;
     }
 
+    /**
+     * 
+     * @param int $id
+     * @return boolean
+     * @throws EntityNotFoundException
+     * @throws ORMInvalidArgumentException
+     */
     public function delete($id)
     {
         if (null === ($entity = $this->em->find(Person::class, $id))) {
-            return false;
+            throw new EntityNotFoundException('No result was found for query although at least one row was expected.');
         }
 
-        try {
-            $this->em->remove($entity);
-            $this->em->flush();
-        } catch (Exception $ex) {
-            return false;
-        }
+        $this->em->remove($entity);
+        $this->em->flush();
 
         return true;
     }