mysql PHP 自动递增列

Question

如何向这些语句中添加一个名为 ID 的自动递增列：

$sql = "CREATE TABLE IF NOT EXISTS ".$username." (uid varchar(255), tweet varchar(255))";
$alter = "ALTER TABLE ".$username." ADD UNIQUE (uid)";

谢谢

Answer 1

我会做

"CREATE TABLE IF NOT EXISTS ".$username." (id MEDIUMINT AUTO_INCREMENT PRIMARY KEY, uid varchar(255) UNIQUE, tweet varchar(255))";

Answer 2

$sql = "CREATE TABLE IF NOT EXISTS ".$username." (ID int not null auto_increment primary key, uid varchar(255), tweet varchar(255))";