Error handling simplified

backend/classes/core/MySqlDatabase.php

@@ -19,7 +19,10 @@ final class MySqlDatabase implements DatabaseInterface
         try {
             $this->connection = new PDO("mysql:host=$hostname;dbname=$database", $user, $password);
         } catch (Throwable $e) {
-            throw new DatabaseException('Couldn\'t connect to the database!');
+            throw new DatabaseException(
+            	'Couldn\'t connect to the database!',
+				ServerStatus::INTERNAL_ERROR
+			);
         }
 	}
 
@@ -138,7 +141,10 @@ final class MySqlDatabase implements DatabaseInterface
         try {
             $this->Query($query, $conditions);
         } catch (Throwable $e) {
-            return [];
+            throw new DatabaseException(
+            	$e->getMessage(),
+				ServerStatus::INTERNAL_ERROR
+			);
         }
 
         return $this->getResult();

backend/classes/core/Table.php

@@ -67,7 +67,10 @@ abstract class Table
                     $type = self::TYPE_BOOL;
                     break;
 				default:
-					throw new Exception(sprintf('Type %s of field %s couldn\'t be handled', $sqlType, $field['Field']));
+					throw new DatabaseException(
+						sprintf('Type %s of field %s couldn\'t be handled', $sqlType, $field['Field']),
+						ServerStatus::INTERNAL_ERROR
+					);
 			}
 
             $this->addField($field['Field'], $type);
@@ -94,8 +97,9 @@ abstract class Table
 	protected function addField(string $name, int $type): void
 	{
 		if (!self::IsValidType($type)) {
-			throw new Exception(
+			throw new DatabaseException(
-			    sprintf('Field %s has invalid type of %s!', $name, $type)
+			    sprintf('Field %s has invalid type of %s!', $name, $type),
+				ServerStatus::INTERNAL_ERROR
             );
 		}
 
@@ -104,19 +108,18 @@ abstract class Table
 
     protected function loadById($id): void
 	{
-        try {
+		$this->database->Query(
-            $this->database->Query(
+			sprintf('SELECT * FROM %s WHERE %s = :id', $this->tableName, $this->primaryKey),
-                sprintf('SELECT * FROM %s WHERE %s = :id', $this->tableName, $this->primaryKey),
+			['id' => $id]
-                ['id' => $id]
+		);
-            );
-        } catch (Throwable $e) {
-            throw new Exception();
-        }
 
 		$result = $this->database->getResult();
 
 		if (count($result) === 0) {
-			throw new Exception(sprintf('No %s with id %d found!', $this->tableName, $id));
+			throw new DatabaseException(
+				sprintf('No %s with id %d found!', $this->tableName, $id),
+				ServerStatus::BAD_REQUEST
+			);
 		}
 
 		foreach ($result[0] as $field => $value) {
@@ -131,11 +134,7 @@ abstract class Table
 
     public function Delete(): void
     {
-        try {
+		$this->database->Delete($this->tableName, [$this->primaryKey => $this->getPrimaryKey()]);
-            $this->database->Delete($this->tableName, [$this->primaryKey => $this->getPrimaryKey()]);
-        } catch (Throwable $e) {
-            throw new Exception();
-        }
 
         foreach ($this->GetAllFieldNames() as $field) {
             $this->fields[$field][self::VALUE] = null;
@@ -157,7 +156,10 @@ abstract class Table
 	protected function setField(string $name, $value): void
 	{
 		if (!$this->HasField($name)) {
-			throw new Exception(sprintf('Field %s doesn\'t exist!', $name));
+			throw new DatabaseException(
+				sprintf('Field %s doesn\'t exist!', $name),
+				ServerStatus::INTERNAL_ERROR
+			);
 		}
 
 		if ($value === null) {
@@ -178,8 +180,11 @@ abstract class Table
 			case self::TYPE_DATETIME:
 				try {
 				    $this->fields[$name][self::VALUE] = new DateTime((string)$value);
-                } catch (Exception $e) {
+                } catch (Throwable $e) {
-                    throw new Exception();
+                    throw new DatabaseException(
+                    	$e->getMessage(),
+						ServerStatus::INTERNAL_ERROR
+					);
                 }
 				return;
             case self::TYPE_BOOL:
@@ -254,7 +259,10 @@ abstract class Table
 	protected function saveWithManualId(array $fields): void
     {
         if ($this->getField($this->primaryKey) === null) {
-            throw new Exception('Manual primary key must not be null!');
+            throw new DatabaseException(
+            	'Manual primary key must not be null!',
+				ServerStatus::INTERNAL_ERROR
+			);
         }
 
         $hasKey = (bool)$this->database->Count(