fetchAll()
array PDOStatement::fetchAll ()
返回一个数组，包含结果集中的所有行(rows)。每一行为一个有列的值的数组，或一个对象，每个属性对应一个列值。没有返回数据时，为一个空数组，异常返回false。
示例：
< ?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
$result = $sth->fetchAll();
print_r($result);
? >
输出结果：
Array
(
    [0] => Array
        (
            [NAME] => pear
            [0] => pear
            [COLOUR] => green
            [1] => green
        )
    [1] => Array
        (
            [NAME] => watermelon
            [0] => watermelon
            [COLOUR] => pink
            [1] => pink
        )
)

fetch(), fetchObject()方法
mixed PDOStatement::fetch()
从结果集中以数组形式返回一行，数组关联索引为列名，或数值索引。
fetchObject()方法以对象形式返回一行，对象属性名为列名。
示例：
< ?php
function readDataForwards($dbh) {
  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY BET';
  try {
    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
    $stmt->execute();
    while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_NEXT)) {
      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
      print $data;
    }
    $stmt = null;
  }
  catch (PDOException $e) {
    print $e->getMessage();
  }
}
function readDataBackwards($dbh) {
  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY bet';
  try {
    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_LAST);
    do {
      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
      print $data;
    } while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_PRIOR));
    $stmt = null;
  }
  catch (PDOException $e) {
    print $e->getMessage();
  }
}

print "Reading forwards:\n";
readDataForwards($conn);

print "Reading backwards:\n";
readDataBackwards($conn);
? >

closeCursor()方法
bool PDOStatement::closeCursor (void)
释放到服务器的连接，已使其他SQL语句可以执行，但同时保留语句状态，可以再次执行。
示例：
< ?php
//Create a PDOStatement object
$stmt = $dbh->prepare('SELECT foo FROM bar');

//Create a second PDOStatement object
$otherStmt = $dbh->prepare('SELECT foobaz FROM foobar');

//Execute the first statement
$stmt->execute();

// Fetch only the first row from the results
$stmt->fetch();

// The following call to closeCursor() may be required by some drivers
$stmt->closeCursor();

// Now we can execute the second statement
$otherStmt->execute();
? >

结果集行、列计数
int PDOStatement::columnCount(void)
int PDOStatement::rowCount (void)

示例一：
< ?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");
? >

示例二：
< ?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");
? >

示例三：
< ?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;
? >