表没有创建PHP mysql数据库

Question

我正在尝试使用PHP和MySQL创建一个表.第一个表不会在数据库上创建,但第二个表将创建.我认为它是我的参数/约束.这是我的代码:

if ($conn==true){
     $tablefriends = "CREATE TABLE IF NOT EXISTS friends (
        friend_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
        friend_email VARCHAR(64) NOT NULL PRIMARY KEY ,
        password VARCHAR(16) NOT NULL ,
        profile_name VARCHAR(32) NOT NULL ,
        date_started DATE NOT NULL ,
        num_of_friends INT UNSIGNED ZEROFILL NULL default '0'
        );";

    $tablemyfriends = "CREATE TABLE IF NOT EXISTS myfirends ( 
        friend_id1 INT NOT NULL , 
        friend_id2 INT NOT NULL 
        );";

    $resulttf = @mysqli_query($conn, $tablefriends);
    if($resulttf==false){
        echo "<p>Failed to create friends table</p>";
        }
    $resulttmf = @mysqli_query($conn, $tablemyfriends);
    if($resulttmf==false){
        echo "<p>Failed to create myfriends table</p>"; 
        }else{

    echo"<p>Tables successfully created</p>";
        }
    mysqli_close($conn);
}

else {
    echo "<p>Failed to connect</p>";
    }

---

我不知道为什么导师说过要两次进入小学

Answer 1

2个主键.friend_id和friend_email

在将它放入PHP之前,请务必检查您的查询.