Printing PDO query results [closed] - php

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I am trying to print all the results of a query, but for some reason I get the following error: Fatal error: Call to a member function fetch() on boolean in H:\Some-Location\ on line X
This is my code:
<?php
$query = "SELECT adID FROM given WHERE toUser = :userid";
$query_params = array( ':userid' => $_SESSION['user']['ID'] );
try
{
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch(PDOException $ex)
{
echo "Failed to run query: " . $ex->getMessage();
}
while ($row = $result->fetch(PDO::FETCH_ASSOC))
{
echo $row['adID'];
}
?>
What's wrong?

Answer 1

As the docs and the error show, execute returns a boolean: http://php.net/manual/en/pdostatement.execute.php
You need to call fetch() on the statement, not the return value of execute. : http://php.net/manual/en/pdostatement.fetch.php
so replace $result>fetch() with $stmt->fetch().

Answer 2

The execute() method on the PDOStatement does not return the results, it only signals if the query succeeded or not (only useful when not using exceptions).
PHP Documentation:
public bool PDOStatement::execute ([ array $input_parameters ] )
What you want to do is use the PDOStatement itself to get the data:
while ($row = $stmt->fetch(PDO::FETCH_ASSOC))
{
echo $row['adID'];
}
Note: According to your current logic, the loop will execute even when an exception is thrown. Try either returning from the catch block or putting the loop inside the try block.

Answer 3

$result is only a boolean holding success/failure of execute statement.
You need to run fetch on $stmt:
while ($row = $stmt->fetch(PDO::FETCH_ASSOC))
{
echo $row['adID'];
}
As per documentation here:
http://php.net/manual/en/pdostatement.fetch.php