SQLite3::openBlob

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    SQLite3::openBlob — Opens a stream resource to read a BLOB

    Beschreibung

    public SQLite3::openBlob(
        string $table,
        string $column,
        int $rowid,
        string $database = "main",
        int $flags = SQLITE3_OPEN_READONLY
    ): resource|false

    Opens a stream resource to read or write a BLOB, which would be selected by:

    SELECT column FROM database.table WHERE rowid = rowid

    Hinweis: It is not possible to change the size of a BLOB by writing to the stream. Instead, an UPDATE statement has to be executed, possibly using SQLite's zeroblob() function to set the desired BLOB size.

    Parameter-Liste

    table

    The table name.

    column

    The column name.

    rowid

    The row ID.

    database

    The symbolic name of the DB

    flags

    Either SQLITE3_OPEN_READONLY or SQLITE3_OPEN_READWRITE to open the stream for reading only, or for reading and writing, respectively.

    Rückgabewerte

    Returns a stream resource, Bei einem Fehler wird false zurückgegeben..

    Changelog

    Version Beschreibung
    7.2.0 The flags parameter has been added, allowing to write BLOBs; formerly only reading was supported.

    Beispiele

    Beispiel #1 SQLite3::openBlob() example

    <?php
    $conn     = new SQLite3(':memory:');
    $conn->exec('CREATE TABLE test (text text)');
    $conn->exec("INSERT INTO test VALUES ('Lorem ipsum')");
    $stream = $conn->openBlob('test', 'text', 1);
    echo     stream_get_contents($stream);
    fclose($stream); // mandatory, otherwise the next line would fail
    $conn->close();
    ?>

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

    Lorem ipsum

    Beispiel #2 Incrementally writing a BLOB

    <?php
    $conn     = new SQLite3(':memory:');
    $conn->exec('CREATE TABLE test (text text)');
    $conn->exec("INSERT INTO test VALUES (zeroblob(36))");
    $stream = $conn->openBlob('test', 'text', 1, 'main', SQLITE3_OPEN_READWRITE);
    for (    $i = 0; $i < 3; $i++) {
    fwrite($stream, "Lorem ipsum\n");
    }
    fclose($stream);
    echo     $conn->querySingle("SELECT text FROM test");
    $conn->close();
    ?>

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

    Lorem ipsum
Lorem ipsum
Lorem ipsum

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