Call to undefined method PDOStatement::numColumns() - php

Question

I can't run the method numColumns() on my $result.
My code:
try {
$db = new PDO('sqlite:temps.sqlite',null,null,array(
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
));
} catch (PDOException $e) {
print 'Exception : ' . $e->getMessage();
}
$result = $db->query("SELECT * FROM data LIMIT 30");
$fields = $result->numColumns();
The error is the following one:
Uncaught Error: Call to undefined method PDOStatement::numColumns() in /*/export.php:7 Stack trace: #0 {main} thrown in /*/export.php on line 7
(line 7 is the last one)
Why does it not work?

Answer 1

You are trying to execute functions from different APIs. You call for PDO, but trying to execute numColumns from SQLite3Result.
As the docs state, PDO::query() returns a PDOStatement object and your error also points you to that:
Call to undefined method PDOStatement::numColumns()
You need to execute columnCount instead:
$result = $db->query("SELECT * FROM data LIMIT 30");
$fields = $result->columnCount();
Or if you wish to work with SQLite3, initialize an SQLite3 connection:
$db = new SQLite3('mysqlitedb.db');
$result = $db->query("SELECT * FROM data LIMIT 30");
$fields = $result->numColumns();