UPDATE or INSERT MySQL Python

问题

I need to update a row if a record already exists or create a new one if it dosen't. I undersant ON DUPLICATE KEY will accomplish this using MYSQLdb, however I'm having trouble getting it working. My code is below

        cursor = database.cursor()
        cursor.execute("INSERT INTO userfan (user_id, number, round VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE user_id =%s, number=%s, round=%s", (user_id, number, round))
        database.commit()

primary key is user_id

回答1:

A parenthesis was missiing. You can also use the VALUES(column) in the ON DUPLICATE KEY UPDATE section of the statement:

    cursor = database.cursor()
    cursor.execute("""
        INSERT INTO userfan 
            (user_id, number, round)
        VALUES 
            (%s, %s, %s) 
        ON DUPLICATE KEY UPDATE 
                                          -- no need to update the PK
            number  = VALUES(number), 
            round   = VALUES(round) ;
                   """, (user_id, number, round)     # python variables
                  )
    database.commit()

来源：https://stackoverflow.com/questions/15465478/update-or-insert-mysql-python