PDOStatement::setFetchMode

    (PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)

    PDOStatement::setFetchMode — 为语句设置默认的获取模式

    说明

    public PDOStatement::setFetchMode(int $mode): bool
    public PDOStatement::setFetchMode(int $mode = PDO::FETCH_COLUMN, int $colno): bool
    public PDOStatement::setFetchMode(int $mode = PDO::FETCH_CLASS, string $class, ?array $constructorArgs = null): bool
    public PDOStatement::setFetchMode(int $mode = PDO::FETCH_INTO, object $object): bool

    参数

    mode

    获取模式必须是 PDO::FETCH_* 常量中的一个。

    colno

    列号。

    class

    类名。

    constructorArgs

    构造方法参数。

    object

    对象。

    返回值

    成功时返回 true， 或者在失败时返回 false。

    示例

    示例 #1 设置获取模式

    以下示例演示了 PDOStatement::setFetchMode() 如何更改 PDOStatement 对象的默认获取模式。

    <?php
    $stmt     = $dbh->query('SELECT name, colour, calories FROM fruit');
    $stmt->setFetchMode(PDO::FETCH_NUM);
    foreach (    $stmt as $row) {
    print     $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
    }

    以上示例的输出类似于：

    apple   red     150
banana  yellow  250
orange  orange  300
kiwi    brown   75
lemon   yellow  25
pear    green   150

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    用户贡献的备注 3 notes

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    35
    Dormilich at netscape dot net
    14 years ago
    if you want to fetch your result into a class (by using PDO::FETCH_CLASS) and want the constructor to be executed *before* PDO assings the object properties, you need to use the PDO::FETCH_PROPS_LATE constant:

    <?php
    $stmt     = $pdo->prepare("your query");

    $stmt->setFetchMode(PDO::FETCH_CLASS|PDO::FETCH_PROPS_LATE, "className", $constructorArguments);

    # pass parameters, if required by the query
    $stmt->execute($parameters);

    foreach (    $stmt as $row)
    {
    // do something with (each of) your object
    }
    ?>
    up
    9
    Kats
    7 years ago
    Something very helpful is knowing how to access namespaces from the function. It took me a minute (and Google) to figure out. The ::class property is going to be your best friend in this case.

    <?php
    $stmt    ->setFetchMode(PDO::FETCH_CLASS, Name\Space\Class::class);
    ?>
    up
    2
    stein_AT_rhrk.uni-kl.de
    16 years ago
    Some note on PDO :: FETCH_CLASS | PDO :: FETCH_CLASSTYPE

    It took me some time, to realize, that you can not use this fetch-mode in $stm->setFetchMode(), when you want to retrieve objects from the database whereas the type is defined by the first column in the resultset.
    You have to define this mode directly in the $stm->fetch() method.

    To make it clearer:

    $stm = $pdo->query("SELECT * FROM `foo`);
    $stm->setFetchMode(FETCH_CLASS | PDO :: FETCH_CLASSTYPE);

    $object = $stm->fetch();

    Will not return the expected object, whereas

    $stm = $pdo->query("SELECT * FROM `foo`");

    $object = $stm->fetch(FETCH_CLASS | PDO :: FETCH_CLASSTYPE);

    will give you the object of the class, defined in the first column of `foo`.
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