Question

我正在尝试获取一个ID和一行名为info的行，以显示用户名。

我有一个用户表：

TABLE users (
id       INTEGER PRIMARY KEY AUTOINCREMENT
                 NOT NULL,
username TEXT    NOT NULL
                 UNIQUE,
password TEXT    NOT NULL

和一个将用户ID作为FK的信息表：

TABLE infos (
infoid  INTEGER NOT NULL
                  PRIMARY KEY AUTOINCREMENT,
info    TEXT    NOT NULL,
productid INTEGER REFERENCES product (productid) 
                  NOT NULL,
userid    INTEGER REFERENCES users (id) 
                  NOT NULL

我设法从会话中获取用户名和用户ID：

// get username
$name = $_SESSION['username'];
$stmt = $db->prepare("SELECT id FROM users WHERE username = :name");
$stmt->execute(["name" => $name]);
$r = $stmt->fetch(); 

// get userid
$stmnt2 = $db->prepare("SELECT info FROM infos WHERE userid = :r");
$stmnt2->execute(["r" => $r['id']]);

我很难根据用户ID获取所有信息ID和信息。我设法得到了信息，但它错过了第一个条目，我无法获得infoid

    // get info based on userid
    if ($info = $stmnt2->fetch()) {
        echo '<p>Your Info:</p>';   
            while ($info = $stmnt2->fetch()) {
            echo "$info[info] </br>";
            }
   } else {
        echo "<p>No Info</p>";

有人可以告诉我如何获得infoid和信息以表示感谢。

Answer 1

替换

// get userid
$stmnt2 = $db->prepare("SELECT info FROM infos WHERE userid = :r");
$stmnt2->execute(["r" => $r['id']]);

与

// get userid
$stmnt2 = $db->prepare("SELECT info, infoid AS id FROM infos WHERE userid = :r");
$stmnt2->execute(["r" => $r['id']]);

并替换

// get info based on userid
if ($info = $stmnt2->fetch()) {
    echo '<p>Your Info:</p>';   
        while ($info = $stmnt2->fetch()) {
        echo "$info[info] </br>";
        }
} else {
    echo "<p>No Info</p>";
}

与

// get info based on userid

if ($info = $stmnt2->fetch()) {
    echo '<p>Your Info:</p>';   
    do {
        echo "$info[info] </br>"; //The info id is contained in the $info['id']
    } while ($info = $stmnt2->fetch());
} else {
    echo "<p>No Info</p>";
}

或

// get info based on userid

if ($stmnt2->num_rows()) {
    echo '<p>Your Info:</p>';   
    while ($info = $stmnt2->fetch()){
        echo "$info[info] </br>"; //The info id is contained in the $info['id']
    }
} else {
    echo "<p>No Info</p>";
}

我会建议你第二种方式。不要犹豫，问我任何解释。

从会话用户名派生的外键ID中获取ID和行

1 个答案: