pdo fetch within a fetch error - php

Question

I am trying to run the following script (unsuccessfully):
$variables = $db->query("SELECT * FROM table1 WHERE Session_ID = '$sess1'");
while($row = $variables->fetch()) {
//FETCH DATA
$id= $row["ID"];
$info = $db->query("SELECT * FROM table2 WHERE ID = $id");
while($row2 = $info->fetch()) {
$name = $row2["FNAME"]." ".$row2["LNAME"]; }
$phone = $row2["PHONE"];
}
//SEND CUSTOMER EMAIL
require("../email/email.php");
}
this returns the error: Fatal error: Call to a member function fetch() on a non-object in...
While I am able to "solve" the problem, it is ugly. Essentially I have to make several calls ahead of the one I'm trying below (which in theory should work).
Any ideas?

Answer 1

As far as I can tell, you have to fetch all results from a resultset before you can issue a new query. If you're using MySQL, you can circumvent that by calling $db->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY,true);, but I would advice against it, as it makes your code less portable, and on of the major plusses of PDO, database-abstraction, is lost.

Answer 2

try this instead
//prepare the query
$variables = $db->prepare("SELECT * FROM table1 WHERE Session_ID = :sess1");
$info = $db->prepare("SELECT * FROM table2 WHERE ID = :ID");
//bind the variable :sess1 to $sess1
$variables->bindParam(':sess1', $sess1, PDO::PARAM_STR);
//execute the query
$variables->execute;
//fetch the result
$result = $variables->fetch(PDO::FETCH_ASSOC);
//set $result['ID'] to a variable and bind it to the variable :ID in our second query
$id = $result['ID'];
$info->bindParam(':ID', $id, PDO::PARAM_INT);
while($row2 = $info->fetch()) {
$name = $row2["FNAME"]." ".$row2["LNAME"]; }
$phone = $row2["PHONE"];
}
//SEND CUSTOMER EMAIL
require("../email/email.php");
}