SQLite3::query

(PHP 5 >= 5.3.0, PHP 7)

SQLite3::query — Executes an SQL query

说明

public SQLite3Result SQLite3::query ( string $query )

Executes an SQL query, returning an SQLite3Result object. If the query does not yield a result (such as DML statements) the returned SQLite3Result object is not really usable. Use SQLite3::exec() for such queries instead.

参数

query

The SQL query to execute.

返回值

Returns an SQLite3Result object, 或者在失败时返回 FALSE.

范例

Example #1 SQLite3::query() example

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

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

User Contributed Notes

paule-panke at example dot com 12-Feb-2017 10:55
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.
bohwaz 13-Mar-2013 08:47
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.
pgarvin76 at gmail dot com 13-Jan-2011 04:31
The notes for the return value is a little misleading to me. It states that if the query does not "return results" TRUE or FALSE is returned instead. If there is a return value for this method in your PHP code this method always returns an SQLite3Result object, even if you accidentally run an INSERT, UPDATE, DELETE, CREATE TABLE, etc query through it. The only time it returns a TRUE or FALSE is if there is no return value.

<?php
$result = $dbh->query('CREATE TABLE ...');
if (!($result instanceof Sqlite3Result)) {
    echo "Query successful."; // This will never echo.
} else {
    $result->fetchArray(); // This will throw an error.
}

if ($dbh->query('CREATE TABLE ...')) {
    echo "Query successful."; // Works
} else {
    echo "Query failed."; // Will also work
}
?>
Use exec() if you are not executing a SELECT query.