Updating row on mysql php -

i want update row on table , not updating. html , php code :

<?php if ($_get) {     if (isset($_get['id'])) {         $id = preg_replace('#[^0-9]#', '', $_get['id']);         echo $id;         $query = "select * posts id='{$id}'";         $result = mysqli_query($connect, $query);         $rows = mysqli_fetch_assoc($result);     } elseif (empty($_get['id'])) {         header("location: manage_posts.php");     } } ?> <form action="modify_post.php?id=<?php echo $id; ?>" method="post">     <h3>post title <?php //echo $id; ?></h3>     <input name="title" value="<?php echo $rows['title'];?>" type="text" placeholder="title here ..." id="title" required>     <h3>post content</h3>     <textarea name="content" required  placeholder="title here ..." style="resize: none"><?php echo $rows['content'];?></textarea>     <br/>     <input type="submit" value="update" id="submit"/> </form> <?php if ($_server['request_method'] === 'post') {      if ($_post['title'] != "" || $_post['content'] != "") {         $id = preg_replace('#[^0-9]#', '', $_get['id']);         $sql = "update posts set title='{$_post['title']}', content='{$_post['content']}' id='{$id}'";         $update_result = mysqli_query($connect, $sql);          if (isset($result)) {             echo "<h2>update successfully, redirecting ...</h2>";         } else {             echo "record hasn't been updated" . mysqli_errno($result);         }          header("location: manage_posts.php");     } else {         echo "<h3>please fill fields</h3>";     } } ?> 

this came !

i don't know problem coming ?

a) avoid sql injections e.g. prepared statements + parameters
b) add more error handling , parameter checking.

<?php if ($_server['request_method'] !== 'post') {     echo 'wrong method'; } else if ( !isset($_post['title'], $_post['content']) ) {     echo 'missing post parameters'; } else if ( !isset($_get['id']) ) {     echo 'missing parameter'; } else if ($_post['title'] == "" || $_post['content'] == "") {     echo '<h3>please fill fields</h3>'; } else {     $stmt = $connect->prepare('update posts set title=?, content=? id=?');     if ( !$stmt ) {         trigger_error('prepare failed', e_user_error);     }     else  if ( !$stmt->bind_param('sss', $_post['title'], $_post['content'], $_get['id']) ) {         trigger_error('bind_param failed', e_user_error);     }     else if ( !$stmt->execute() ) {         trigger_error('execute failed', e_user_error);     }     else {           echo '# of updated rows: ', $stmt->affected_rows();     } } 

see

• http://docs.php.net/mysqli.error-list
• http://docs.php.net/mysqli-stmt.error-list