Пример 2. Counting rows returned by a SELECT statement
For most databases, PDOStatement::rowCount() does not
return the number of rows affected by a SELECT statement. Instead, use
PDO::query() to issue a SELECT COUNT(*) statement
with the same predicates as your intended SELECT statement, then use
PDOStatement::fetchColumn() to retrieve the number
of rows that will be returned. Your application can then perform the
correct action.
<?php
$sql = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
if ($res = $conn->query($sql)) {
// Check the number of rows that match the SELECT statement
if ($res->fetchColumn() > 0) {
// Issue the real SELECT statement and work with the results
$sql = "SELECT name FROM fruit WHERE calories > 100";
foreach ($conn->query($sql) as $row) {
print "Name: " . $row['NAME'] . "\n";
}
}
// No rows matched -- do something else
else {
print "No rows matched the query.";
}
}
$res = null;
$conn = null;
?>
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Результат выполнения данного примера:
