CODEWITHSUNDEEP
phpsqlfetch
shakked
shakked

Reputation: 811

when do you use fetch() with SQL and php?

I am a little confused on when you use the fetch() method and when you do not. Like in this case:

Why do I need the fetch() method here:

$query = "SELECT * FROM Idea_Categories WHERE categoryID = $category_id";
$category = $db->query($query);
$category = $category->fetch();
$category_id = $category['categoryID'];
$category_name = $category['categoryName'];

But not here:

$query = "SELECT * FROM statements WHERE categoryID = $category_id ORDER BY entryID";
$statements = $db->query($query);

I use $statements here and it just lists all the statements I have in the database:

<table>
    <?php foreach ($statements as $statement) :?>
    <tr>
            <td><?php echo $statement['topic']; ?></td>
            <td>
                <form action="delete_line.php" method="post">
                    <input type="hidden" name="topic" value="<?php echo $statement['topic'];?>" /> 
                    <input type="hidden" name="category_id" value="<?php echo $statement['categoryID'];?>" /> 
                    <input type="submit" value="Delete" />
                </form>                          
            </td>
            <td>
                <form action="product_rate.php" method="post">
                    <input type="hidden" name="topic" value="<?php echo $statement['topic'];?>" />
                    <input type="submit" value="Upvote" name="action" />
                </form>
            </td>
            <td>
                <form action="product_rate.php" method="post">
                    <input type="hidden" name="topic" value="<?php echo $statement['topic'];?>" />
                    <input type="submit" value="Downvote" name="action"/>
                </form>
            </td>

    </tr>
    <?php endforeach; ?>

Upvotes: 0

Views: 91

Answers (1)

deceze
deceze

Reputation: 522523

PDO::query returns a PDOStatement object. Any time you are handling a result set with PDO you have such an object. Usually you call PDOStatement::fetch on it to get the results, often in a loop like this:

while ($row = $stmt->fetch()) ...

PDOStatement also implements the Traversable interface though, which simply enables you to do exactly the same thing as above, but using foreach:

foreach ($stmt as $row) ...

It's just a bit of syntactic sugar thanks to the Traversable interface, which you can implement in any of your own classes as well.

Upvotes: 1

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