Update if record doesn't exist in MySQL DB

This is my table: (unique master key alias

)

$sql = "CREATE TABLE IF NOT EXISTS Articls 
        (
            id INT(10) UNSIGNED AUTO_INCREMENT PRIMARY KEY,     
            name VARCHAR(254) COLLATE utf8_persian_ci NOT NULL,                 
            alias INT(10) UNSIGNED NOT NULL,                                 # alias name for url
            title VARCHAR(254) NOT NULL COLLATE utf8_persian_ci NOT NULL,
            UNIQUE (alias)
        )   DEFAULT COLLATE utf8_persian_ci";

      

        
        
        
      

    

So, I want to insert a new record into the DB if alias

doesn't exist in the table, or update the table if an alias existed previously.

I have tried this with no success.

$sqlname = "name,alias,title";

$sqlValue =  "'".$node['name']."','".$node['alias']."','".$node['title']."'";

$sql = "INSERT INTO Articls (".$sqlname.") 
                    VALUES (".$sqlValue.")
        ON DUPLICATE KEY UPDATE
            (".$sqlname.") VALUES (".$sqlValue.")";

      

        
        
        
      

    

I've also tried this code with no success ... It just creates a new entry and doesn't update:

$sql = "INSERT INTO Articls (".$sqlname.") 
                    VALUES (".$sqlValue.")

            ON DUPLICATE KEY UPDATE title = 'test',alias = '".$node['alias']."'";