PDOStatement::columnCount
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)
PDOStatement::columnCount — Returns the number of columns in the result set
Beschreibung
Use PDOStatement::columnCount() to return the number of columns in the result set represented by the PDOStatement object.
If the PDOStatement object was returned from PDO::query(), the column count is immediately available.
If the PDOStatement object was returned from PDO::prepare(), an accurate column count will not be available until you invoke PDOStatement::execute().
Parameter-Liste
Diese Funktion besitzt keine Parameter.
Rückgabewerte
Returns the number of columns in the result set represented by the
PDOStatement object, even if the result set is empty. If there is no result set,
PDOStatement::columnCount() returns 0.
Beispiele
Beispiel #1 Counting columns
This example demonstrates how PDOStatement::columnCount() operates with and without a result set.
<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
/* Count the number of columns in the (non-existent) result set */
$colcount = $sth->columnCount();
print("Before execute(), result set has $colcount columns (should be 0)\n");
$sth->execute();
/* Count the number of columns in the result set */
$colcount = $sth->columnCount();
print("After execute(), result set has $colcount columns (should be 2)\n");
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Before execute(), result set has 0 columns (should be 0) After execute(), result set has 2 columns (should be 2)
Siehe auch
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::execute() - Führt ein Prepared Statement aus
- PDOStatement::rowCount() - Returns the number of rows affected by the last SQL statement
