SQLite3::openBlob

(PHP 5 >= 5.3.0, PHP 7)

SQLite3::openBlobOpens a stream resource to read a BLOB

Описание

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

Замечание: 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.

Список параметров

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.

Возвращаемые значения

Returns a stream resource, или FALSE в случае возникновения ошибки.

Список изменений

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

Примеры

Пример #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();
?>

Результат выполнения данного примера:

Lorem ipsum

Пример #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();
?>

Результат выполнения данного примера:

Lorem ipsum
Lorem ipsum
Lorem ipsum

add a note add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top