(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
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().
У цієї функції немає параметрів.
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.
Видає помилку рівня E_WARNING, якщо атрибут
PDO::ATTR_ERRMODE дорівнює
PDO::ERRMODE_WARNING.
Викидає PDOException, якщо атрибут
PDO::ATTR_ERRMODE дорівнює
PDO::ERRMODE_EXCEPTION.
Приклад #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";
?>Поданий вище приклад виведе:
Before execute(), result set has 0 columns (should be 0) After execute(), result set has 2 columns (should be 2)