爲什麼我不能讓這個數據庫工作？

Question

美好的一天我有問題讓這個數據庫工作使用電子郵件，而不是用戶名，但它似乎並沒有工作。有解釋的解決方案將受到高度讚賞。謝謝你在前進

$tbl_users = "CREATE TABLE IF NOT EXISTS users (
    id INT (11) NOT NULL AUTO_INCREMENT, 
    firstname VARCHAR (16) NOT NULL, 
    lastname VARCHAR (16) NOT NULL, 
    username VARCHAR (16) NOT NULL, 
    age VARCHAR (16) NOT NULL, 
    gender ENUM ('m','f') NOT NULL, 
    email VARCHAR (255) NOT NULL, 
    website VARCHAR (255) NULL, 
    country VARCHAR (255) NULL, 
    userlevel ENUM ('a','b','c','d') NOT NULL DEFAULT 'a', 
    avatar VARCHAR (255) NULL, 
    ip VARCHAR (255) NOT NULL, 
    signup DATETIME NOT NULL, 
    lastlogin DATETIME NOT NULL, 
    notescheck DATETIME NOT NULL, 
    activated ENUM ('0','1') NOT NULL DEFAULT '0', 
    PRIMARY KEY (id), 
    UNIQUE KEY email 
    )"; 
$query = mysqli_query ($db_conx, $tbl_users); 
if ($query === TRUE) { 
    echo "<h3>user table created</h3>"; 
} else { 
    echo "<h3>user table not created</h3>"; 
} 

Answer 1

我認爲你需要UNIQUE KEY (email)與() - 見文檔here和​​