mysqli_query“INSERT into”

Question

我使用此代码，但它不会插入我的数据库..请帮助我

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')"
    );  

数据库集ID自动增量。

Answer 2

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

然后运行sql

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

Answer 3

mysqli_query（$ link，“ INSERT INTO usertable VALUES（NULL，$ username'，'$ password'）“）;