如果MySQL DB中不存在记录，则更新

Question

This is my table: (the unique main key is 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 to the DB if alias does not exist in the table or update the table if the alias already existed before.

I tried this without 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 also tried this code with no success... It just creates a new record and doesn't update:

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

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

Answer 1

The synthax:

ON DUPLICATE KEY UPDATE
        (".$sqlname.") VALUES (".$sqlValue.")";

is not correct.
Use:

ON DUPLICATE KEY UPDATE <fieldname> = <fieldvalue>, <fieldname> = <fieldvalue>...