How to Log MySQL Errors in WordPress

How to Log MySQL Errors in WordPress — Bright Bright Great

MySQL query errors can be difficult to diagnose and correct. For performance reasons, most MySQL installations fail to retain an error log for posterity; inste…

brightbrightgreat.com

//-------------------------------------------------
// Database logging - query errors
//
// email database query errors to the contact
// specified
//
// @param n/a
// @return n/a

function db_debug_log(){

	//WP already stores query errors in this obscure
	//global variable, so we can see what we've ended
	//up with just before shutdown
	global $EZSQL_ERROR;

	try {
		//proceed if there were MySQL errors during runtime
		if(is_array($EZSQL_ERROR) && count($EZSQL_ERROR)) {
			//build a log entry
			$xout = array();

			//let's start with some environmental information
			$xout[] = "DATE: " . current_time('r');
			$xout[] = "SITE: " . site_url();
			$xout[] = "IP: " . $_SERVER['REMOTE_ADDR'];
			$xout[] = "UA: " . $_SERVER['HTTP_USER_AGENT'];
			$xout[] = "SCRIPT: " . $_SERVER['SCRIPT_NAME'];
			$xout[] = "REQUEST: " . $_SERVER['REQUEST_URI'];
			$xout[] = "\n\n\n\n";

			//and lastly, add the error messages with some line separations for readability
			foreach($EZSQL_ERROR AS $e) {
				$xout[] = str_repeat('-', 50) . "\n" . implode("\n", $e) . "\n" . str_repeat('-', 50);
				$xout[] = "\n\n\n\n";
			}

			//email it!
			//if a plugin overrides the content-type header for outbound emails, change the message body
			//below to nl2br(esc_html(implode("\n", $xout)))
			wp_mail(get_bloginfo('admin_email'), '[' . get_bloginfo('name') . '] DB Error', implode(“\n”, $xout));
		}
	} catch(Exception $e){ }

	return;
}
add_action('shutdown', 'db_debug_log');