SQLite3::openBlob

(PHP 5 >= 5.3.0, PHP 7)

SQLite3::openBlobOpens a stream resource to read a BLOB

Beschreibung

public resource SQLite3::openBlob ( string $table , string $column , int $rowid [, string $dbname = "main" [, int $flags = SQLITE3_OPEN_READONLY ]] )

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

SELECT column FROM dbname.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.

dbname

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.

R├╝ckgabewerte

Returns a stream resource, Im Fehlerfall wird FALSE zur├╝ckgegeben..

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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