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We have all the variables set for our pagination, so let’s start adding our limits. We are going to be limiting the number of products we show on a page, so we want to add limits to our catalog calls. This will tell the database to only return a limited number of items. Again, reducing the amount of data the page has to handle.
Example Code
function category_catalog_array($category, $limit = null, $offset = 0) {
include("connection.php");
$category = strtolower($category);
try {
$sql = "SELECT media_id, title, category,img
FROM Media
WHERE LOWER(category) = ?
ORDER BY
REPLACE(
REPLACE(
REPLACE(title,'The ',''),
'An ',
''
),
'A ',
''
)";
if (is_integer($limit)) {
$results = $db->prepare($sql . " LIMIT ? OFFSET ?");
$results->bindParam(1,$category,PDO::PARAM_STR);
$results->bindParam(2,$limit,PDO::PARAM_INT);
$results->bindParam(3,$offset,PDO::PARAM_INT);
} else {
$results = $db->prepare($sql);
$results->bindParam(1,$category,PDO::PARAM_STR);
}
$results->execute();
} catch (Exception $e) {
echo "Unable to retrieved results";
exit;
}
$catalog = $results->fetchAll();
return $catalog;
}
We have all the variables set for pagination. 0:00 So let's start adding our limits. 0:03 We're going to be limiting the number of items we show on each page. 0:05 So we want to add the limits to our catalog calls. 0:09 This will tell the database to only return a limited number of items. 0:12 Again, reducing the amount of data the page has to handle. 0:17 Let's go into our functions page. 0:22 In our catalog array we'll need to pass some optional arguments again. 0:25 We'll do this with limit = null and 0:29 offset = 0. 0:33 Remember by giving a parameter a default value 0:37 we do not require that the argument be passed. 0:40 If we were to call the function full catalog array without passing these 0:44 arguments, we would not have a limit and our offset would be set to 0. 0:48 By setting the offset default to 0, we can then pass a limit without an offset. 0:53 And it would start at the very first item. 0:58 If we don't have a limit, we should return all the items in our catalogue. 1:01 We'll need to add these limits to our SQL statement. 1:05 So let's move our current query into a SQL variable. 1:08 We'll then change our method to prepare and add an execute. 1:20 We haven't changed any functionality yet, but now we can use a conditional and 1:30 add our limits. 1:34 We could use MP again here, but let's be a little more specific. 1:35 We'll use a new built in function called is_, And we'll pass our limit. 1:40 We're going to add a limit, so let's duplicate this line. 1:47 We use this line in our else-statement. 1:52 And we'll leave our execute outside. 1:58 Let's go back up and at our limit with placeholders. 2:01 Limit tells us how many items we want to return and offset tells us where to start. 2:11 We'll use our PDO::PARAM_INT to filter for an integer. 2:29 And the same thing for our offset. 2:50 We need to make these changes to our category catalog array function as well. 2:53 We'll start by adding our optional parameters, limit and offset. 2:57 Again, we'll move our SQL statement out of our prepare. 3:07 And then we can add to it. 3:26 Let's copy the if statement from our full catalog and paste it here. 3:27 We need to change our bind params a little because this statement already 3:42 has a parameter. 3:45 We'll copy this line for 1. 3:51 And then we'll change these to 2 and 3. 3:55 We close out our else before the execute, so both of these will get executed. 3:58 Great, our functions are now set up. 4:02 So we need to pass in the limit and the offset. 4:05 Let's go back to the catalog.php page. 4:07 Let's scroll down to where we're sending our catalog variables. 4:10 We'll pass in the items per page which is our limit, and our offset. 4:16 Will also add this to our category catalog array. 4:23 Now, let's go back to our browser and refresh our full catalog page. 4:38 Perfect. 4:45 Well except for 4:47 the fact that we can't see any more than eight items yet, let's fix that. 4:48
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