php - Do not update with empty vars on UPDATE statement -

i trying run sql update dont want update when post vars empty.

code run :

require '../includes/db.php'; $settings_owner = ( isset($_post[wb_owner_field]) ? $_post[wb_owner_field] : false ); $settings_title = ( isset($_post[wb_title_field]) ? $_post[wb_title_field] : false ); $settings_description = ( isset($_post[wb_descr_field]) ? $_post[wb_descr_field] : false ); $settings_keywords = ( isset($_post[wb_keywd_field]) ? $_post[wb_keywd_field] : false ); $settings_id = ( isset($_post[wb_id]) ? $_post[wb_id] : false );  try {     $sql = "update website  set  website_owner = '$settings_owner', website_title = '$settings_title', website_description = '$settings_description', website_keywords = '$settings_keywords'  _id = '$settings_id'  ";      // prepare statement     $stmt = $conn->prepare($sql);      // execute query     $stmt->execute();      // echo message update succeeded     echo $stmt->rowcount() . " records updated successfully"; } catch (pdoexception $e) {     echo $sql . "<br>" . $e->getmessage(); }  $conn = null; 

one way test value in update statement:

$sql = "update website       set  website_owner = if('$settings_owner' = '', website_owner, '$settings_owner'),          website_title = if('$settings_title' = '', website_title, '$settings_title'),          website_description = if('$settings_description' = '', website_description, '$settings_description'),          website_keywords = if('$settings_keywords' = '',  website_keywords, '$settings_keywords')      _id = '$settings_id'  "; 

another way build update statement dynamically.

$sets = array(); if ($settings_owner != '') {     $sets[] = "website_owner = '$settings_owner'"; } if ($settings_title != '') {     $sets[] = "website_title = '$settings_title'"; } ... if (!empty($sets)) {     $sql = "update website set " . implode(', ', $sets) . " _id = '$settings_id'";     $stmt = $conn->prepare($sql);     $stmt->execute(); }