SQLite3::openBlob

(PHP 5 >= 5.3.0, PHP 7)

SQLite3::openBlobOpens a stream resource to read a BLOB

Opis

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

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

SELECT column FROM dbname.table WHERE rowid = rowid

Informacja: 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.

Parametry

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.

Zwracane wartości

Returns a stream resource, lub FALSE w przypadku niepowodzenia.

Rejestr zmian

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

Przykłady

Przykład #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();
?>

Powyższy przykład wyświetli:

Lorem ipsum

Przykład #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();
?>

Powyższy przykład wyświetli:

Lorem ipsum
Lorem ipsum
Lorem ipsum

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