mysqli_query「INSERT INTO」

Question

我用這個代碼，但它這麼想的插入我的數據base..please幫我

mysqli_query($link, 
      "INSERT INTO `usertable`(`id`, `username`, `password`) 
      VALUES (NULL,'$username','$password')" 
     ); 

Answer 1

mysqli_query("INSERT INTO `usertable`(`username`, `password`) 
     VALUES ('$username','$password')" 
    ); 

數據庫集ID自動遞增。

Answer 2

mysqli_query($link, 
      "INSERT INTO `usertable`(`username`, `password`) 
      VALUES ('$username','$password')" 
     ); 

然後運行丟失的詳細信息的SQL

ALTER TABLE `usertable` CHANGE `id` `id` INT(11) NOT NULL AUTO_INCREMENT;