SQLite3::query

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

SQLite3::query — Führt eine SQL-Anfrage aus

Beschreibung

public SQLite3::query(string $query): SQLite3Result|false

Führt eine SQL-Anfrage aus, welche ein SQLite3Result-Objekt zurück gibt. Liefert die Abfrage kein Ergebnis (so wie DML Anweisungen), dann ist das zürckgelieferte SQLite3Result-Objekt nicht wirklich nutzbar. Statt dessen sollte für solche Abfragen SQLite3::exec() verwendet werden.

Parameter-Liste

query: Die auszuführende SQL-Anfrage.

Rückgabewerte

Liefert ein SQLite3Result-Objekt. Bei einem Fehler wird false zurückgegeben..

Beispiele

Beispiel #1 SQLite3::query()-Beispiel

<?php
$db = new SQLite3('mysqlitedb.db');

$results = $db->query('SELECT bar FROM foo');
while ($row = $results->fetchArray()) {
    var_dump($row);
}
?>

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User Contributed Notes 2 notes

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bohwaz ¶

11 years ago

The recommended way to do a SQLite3 query is to use a statement. For a table creation, a query might be fine (and easier) but for an insert, update or select, you should really use a statement, it's really easier and safer as SQLite will escape your parameters according to their type. SQLite will also use less memory than if you created the whole query by yourself. Example:

<?php

$db = new SQLite3;
$statement = $db->prepare('SELECT * FROM table WHERE id = :id;');
$statement->bindValue(':id', $id);

$result = $statement->execute();

?>

You can also re-use a statement and change its parameters, just do $statement->reset(). Finally don't forget to close a statement when you don't need it anymore as it will free some memory.

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paule-panke at example dot com ¶

7 years ago

Check with SQLite3Result::numColumns() for an empty result before calling SQLite3Result::fetchArray().

In contrast to the documentation SQLite3::query() always returns a SQLite3Result instance, not only for queries returning rows (SELECT, EXPLAIN). Each time SQLite3Result::fetchArray() is called on a result from a result-less query internally the query is executed again, which will most probably break your application.
For a framwork or API it's not possible to know in before whether or not a query will return rows (SQLite3 supports multi-statement queries). Therefore the argument "Don't execute query('CREATE ...')" is not valid.

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