WordPress Insert or Update statement

index.php

function update_globals(){
    
	if (!is_user_logged_in()) exit();
	
	global $wpdb;

	$doesExist = $wpdb->get_row( "SELECT * FROM table WHERE id = " . get_current_user_id() );

	// Update array
	$upValues = isset($_REQUEST) ? $_REQUEST : false;
	
	// unset values if needed
	//unset($upValues['action']);

	if(false === $upValues){

		echo json_encode(array(
			'error' => true,
			'message' => 'No values sent to the request'
		));

	}

	if(!empty($doesExist)){
		
		$query = $wpdb->update( 
		'table', 
			$upValues, 
			array( 'id' => get_current_user_id() )
		);

		if(false === $query){

			echo json_encode(array(
				'error' => true,
				'message' => 'There has been a error'
			));

		}else{

			echo json_encode(array(
				'error' => false,
				'message' => 'Successfully updated'
			));

		}
		
	}else{

		// Add the user id to array
		$upValues['id'] = get_current_user_id();
		$query = $wpdb->insert( 
			'table', 
			$upValues
		);

		if(false === $query){

			echo json_encode(array(
				'error' => true,
				'message' => 'There has been a error'
			));

		}else{

			echo json_encode(array(
				'error' => false,
				'message' => 'Successfully inserted'
			));

		}

	}
	
    die(); 
}