从mysql查询中选择行并将其保存到变量

Question

How can I select a row from mysql query and save it to variable using PDO? Previously I did it like this

$row = mysql_fetch_array($result);

  $ID = $row['ID'];

Now i read from the PHP manual that PDOStatement::fetch() is alternative to mysql_fetch_array but I can't figure out how to use it. This is what I tried but obviously it doesn't work

 <?php
include 'config.php';

$sql = "select * from table1";

try {
    $dbh = new PDO("mysql:host=$dbhost;dbname=$dbname", $dbuser, $dbpass);  
    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $stmt = $dbh->query($sql);  
    $result = $stmt->fetchAll(PDO::FETCH_OBJ);
    $dbh = null;
    echo '{"items":'. json_encode($result) .'}'; 
} catch(PDOException $e) {
    echo '{"error":{"text":'. $e->getMessage() .'}}'; 
}

$row = $stmt->fetchAll(PDO::FETCH_OBJ);
  $ID = $row['ID'];


?>

Answer 1

If you're using PDO::FETCH_OBJ , you must use object notation to retrieve elements in the result. Since you had already called a fetchAll() method, you cannot call another fetch/fetchAll method later on as the data will no longer be accessible.

In place of $row = $stmt->fetchAll(PDO::FETCH_OBJ); , iterate over the $result variable that you previously had fetchAll() return into:

foreach($result as $row)
{
    $ID = $row->ID;
    // Etc...
}