[ADDED]

ext-json to composer as required, because of json_encode and json_decode methods;
own file for every exception class, for better structure;
like functionality;
[UPDATED]
name spaces of Traits and Exceptions;
file names of traits;
[FIXED]
missing @throws tags;
wrong behavior of verifyWhereConditions method if condition is not matched by any if statements;

Author: Timu57

composer.json

@@ -11,7 +11,8 @@
     }
   ],
   "require": {
-    "php": ">=5.4"
+    "php": ">=5.4",
+    "ext-json": "*"
   },
   "autoload": {
     "psr-4": {

src/Exceptions/ConditionNotAllowedException.php

@@ -0,0 +1,6 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+class ConditionNotAllowedException extends \Exception {}

src/Exceptions/EmptyConditionException.php

@@ -0,0 +1,6 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+class EmptyConditionException extends \Exception {}

src/Exceptions/EmptyFieldNameException.php

@@ -0,0 +1,7 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+
+class EmptyFieldNameException extends \Exception {}

src/Exceptions/EmptyStoreDataException.php

@@ -0,0 +1,6 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+class EmptyStoreDataException extends \Exception {}

src/Exceptions/EmptyStoreNameException.php

@@ -0,0 +1,6 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+class EmptyStoreNameException extends \Exception {}

src/Exceptions/IOException.php

@@ -0,0 +1,7 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+
+class IOException extends \Exception {}

src/Exceptions/IdNotAllowedException.php

@@ -0,0 +1,7 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+
+class IdNotAllowedException extends \Exception {}

src/Exceptions/IndexNotFoundException.php

@@ -0,0 +1,7 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+
+class IndexNotFoundException extends \Exception {}

src/Exceptions/InvalidConfigurationException.php

@@ -0,0 +1,6 @@
+<?php
+
+
+namespace SleekDB\Exceptions;
+
+class InvalidConfigurationException extends \Exception {}