PDO: FetchAll after SQL INSERT and SELECT multiple statement in one execute - php

Question

I need to know how to get the result of a select statement that is executed after an insert statement as one execute in PDO.
My PDO connection parameters are as follows:
$opt = [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, PDO::ATTR_EMULATE_PREPARES => true];
$conn = new PDO($dsn, $user, $pass, $opt);
I have the following helper function that i use for my PDO statement Execution:
function databaseExecute($SQL, $BIND_P, &$BIND_R) {
global $conn;
$stmt = $conn->prepare($SQL);
if ($stmt->execute($BIND_P)) {
if ($BIND_R !== false) {
//Type testing is important here
$tmp = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->closeCursor();
if (!$tmp || count($tmp) == 0) {
return false;
}
$BIND_R = $tmp;
} else {
$stmt->closeCursor();
}
return true;
}
$stmt->closeCursor();
return false;
}
My function itself is:
/**
* Adds the current purchase object to the database table
* #return true if success
*/
public function pushToDB() {
global $tbl_purchases;
//We don't push purchaseID since that field is auto handled by the database
$sql = "INSERT INTO " . $tbl_purchases . " (ProductID, UID, TID, GenDate, KeyIDs, Total, Assigned) VALUES (?, ?, ?, ?, ?, ?, ?); SELECT LAST_INSERT_ID();";
$result = array();
if (databaseExecute($sql, array(
$this->getProductID(),
$this->getUID(),
$this->getTID(),
$this->getGenDate(),
$this->getKeyIDsJSON(),
$this->getTotal(),
$this->getAssigned(),
), $r)) {
var_dump($result);
$this->_setPurchaseID($result[0]);
return true;
}
trigger_error("Purchase::pushToDB - Could not push purchase to database", E_USER_ERROR);
return false;
}
But this throws a general error
Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error when i attempt to fetchAll
In this situation, how do i get the result of the SQL execution?
PS: Using Two executes is not acceptable here.

Answer 1

Using Two executes is not acceptable here.
This is but a delusion.
Use either second query or - better - a dedicated function PDO::LastInsertId(). But with your rather poorly designed function it could be a problem. So be it 2 queries.
So change your functions to
function databaseExecute($SQL, $BIND_P = array();) {
global $conn;
if (!$BIND_P)
{
return $conn->query($SQL);
}
$stmt = $conn->prepare($SQL);
$stmt->execute($BIND_P);
return $stmt;
}
and
public function pushToDB() {
global $tbl_purchases;
//We don't push purchaseID since that field is auto handled by the database
$sql = "INSERT INTO $tbl_purchases
(ProductID, UID, TID, GenDate, KeyIDs, Total, Assigned)
VALUES (?, ?, ?, ?, ?, ?, ?)";
databaseExecute($sql, array(
$this->getProductID(),
$this->getUID(),
$this->getTID(),
$this->getGenDate(),
$this->getKeyIDsJSON(),
$this->getTotal(),
$this->getAssigned(),
));
$id = databaseExecute("SELECT LAST_INSERT_ID()")->fetchColumn();
$this->_setPurchaseID($db);
return true;
}
}

Answer 2

You can alter your databaseExectute function to take an extra parameter of 'SecondResult' (for example), then change it to something like...
function databaseExecute($SQL, $BIND_P, &$BIND_R,$SecondResult) {
global $conn;
$stmt = $conn->prepare($SQL);
if ($stmt->execute($BIND_P)) {
if ($BIND_R !== false) {
//Type testing is important here
if ($SecondResult) $stmt->nextRowSet(); // this will ensure that the fetchAll will return the data from the 2nd query
$tmp = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->closeCursor();
if (!$tmp || count($tmp) == 0) {
return false;
}
$BIND_R = $tmp;
} else {
$stmt->closeCursor();
}
return true;
}
$stmt->closeCursor();
return false;
}
I just typed this in to here directly, I haven't tested it, but it should work.
Also, I'm not saying that the other comments are wrong, and there might be a better way of doing this, but you CAN run two queries within the same 'statement'.