PDOStatement::rowCount

Returns the number of rows affected by the last SQL statement

Beschreibung

public int PDOStatement::rowCount ( void )

PDOStatement::rowCount returns the number of rows affected by the last DELETE, INSERT, or UPDATE statement executed by the corresponding PDOStatement object.

If the last SQL statement executed by the associated PDOStatement was a SELECT statement, some databases may return the number of rows returned by that statement. However, this behaviour is not guaranteed for all databases and should not be relied on for portable applications.

Rückgabewerte

Returns the number of rows.

Beispiele

Beispiel #1 Return the number of deleted rows

PDOStatement::rowCount returns the number of rows affected by a DELETE, INSERT, or UPDATE statement.


<?php
/* Delete all rows from the FRUIT table */
$del = $dbh->prepare('DELETE FROM fruit');
$del->execute();

/* Return number of rows that were deleted */
print("Return number of rows that were deleted:\n");
$count = $del->rowCount();
print("Deleted $count rows.\n");
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

Return number of rows that were deleted:
Deleted 9 rows.

Beispiel #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;
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

apple
banana
orange
pear

Siehe auch

PDOStatement::columnCount
PDOStatement::fetchColumn
PDO::query