Merge pull request #5 from jr-cologne/jr_improve_update_method

Improve update() method and sql queries in example

Author: jr-cologne

DB.php

@@ -161,13 +161,17 @@ public function update(string $sql, array $values) {
         $statement = $pdo->prepare($sql);
 
         $execution = $statement->execute($values);
+
+        $affected_rows = $statement->rowCount();
       } catch (PDOException $e) {
         $this->error = [ 'code' => 5, 'msg' => $error_types[5], 'pdo_exception' => $e ];
         return $this->getError();
       }
 
-      if ($execution) {
+      if ($execution && $affected_rows > 0) {
         return true;
+      } else if ($execution && $affected_rows == 0) {
+        return 0;
       } else {
         return false;
       }

README.md

@@ -232,6 +232,15 @@ You can update data in your database by the method `update()`, which has this fo
 update(string $sql, array $values)
 ```
 
+The method has the following return values:
+
+`true`: 	Everything has been updated successfully
+
+`0`:		The query has been executed successfully, but no rows have been affected by it.
+
+`false`:	The query is completely failed.
+
+
 That leads to the following arguments:
 
 #### SQL Query (`$sql`)

example.php

@@ -25,7 +25,7 @@
   echo 'You are successfully connected to the database!<br><br>';
 
   for ($i=1; $i <= 10; $i++) {
-    $inserted[] = $db->insert("INSERT INTO users (id, username, password) VALUES (:id, :username, :password)", [ 'id' => $i, 'username' => 'test' . $i, 'password' => 'hello' . $i ]);
+    $inserted[] = $db->insert("INSERT INTO `users` (id, username, password) VALUES (:id, :username, :password)", [ 'id' => $i, 'username' => 'test' . $i, 'password' => 'hello' . $i ]);
   }
 
   $data_inserted = 0;
@@ -42,7 +42,7 @@
     echo 'Some errors are occured when trying to insert data to the database.<br><br>';
   }
 
-  $data = $db->select("SELECT * FROM users");
+  $data = $db->select("SELECT * FROM `users`");
 
   if (!empty($data)) {
     echo 'Your data:<br><br>';
@@ -51,7 +51,7 @@
     echo 'An error is occured when trying to get your data from the database or there is no data.<br><br>';
   }
 
-  $deleted = $db->delete("DELETE FROM users");
+  $deleted = $db->delete("DELETE FROM `users`");
 
   if ($deleted === true) {
     echo 'Your data has been successfully deleted from the database.<br><br>';