PDOStatement::rowCount

PHP PDO Reference Manual

PDOStatement::rowCount — Returns the number of rows affected by the last SQL statement (PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)

Description

Syntax

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 behavior is not guaranteed for all databases and should not be relied upon for portable applications.

Return Values

Returns the number of rows.

Examples

Return the number of deleted rows

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

<?php
/*  从 FRUIT 数据表中删除所有行 */
$del = $dbh->prepare('DELETE FROM fruit');
$del->execute();

/*  返回被删除的行数 */
print("Return number of rows that were deleted:\n");
$count = $del->rowCount();
print("Deleted $count rows.\n");
?>

The above example outputs:

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

Calculate the number of 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 conditions as the intended SELECT statement, then use PDOStatement::fetchColumn() to retrieve the next row. This allows the application to work correctly.

<?php
$sql = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
if ($res = $conn->query($sql)) {

    /* 检查符合 SELECT 语句的行数 */
  if ($res->fetchColumn() > 0) {

        /* 发出一条真正的 SELECT 语句并操作返回的结果 */
         $sql = "SELECT name FROM fruit WHERE calories > 100";
       foreach ($conn->query($sql) as $row) {
           print "Name: " .  $row['NAME'] . "\n";
         }
    }
    /* 没有匹配的行 -- 执行其他 */
  else {
      print "No rows matched the query.";
    }
}

$res = null;
$conn = null;
?>

The above example outputs:

apple
banana
orange
pear

PHP PDO Reference Manual