Query Caching¶

Query caching is done simply with the help of the Cache Base Model that extends from the Base Model class, and thus providing all the same functionality and more in terms of caching. But before the Cache Base Model can be extended the Cache component must be installed, along with the cache-database sub-component.

When all the requirements have been met, simply extend all the models that will be using the cache from the \SlaxWeb\Cache\Database\Model class.

Using the model¶

The model is used as any other model, everything is handled automatically. When you select data from the database, the Cache Model will calculate a hash from the WHERE statement and the column list, and save the retrieved Result object with in the cache, and simply retrieve that same Result object from it, if it is not expired.

The full name of the data is, database_<tableName><customCacheName>_<hash>.

Where:

tableName is the name of the table in use by the model
customCacheName is the custom name for the data that can be set with the setCacheName
hash is the above calculated cache from the WHERE statement and the column list

Example:

<?php
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel->where("id", 1)->select(["text"]); // will execute the query and store it to cache
// code ...

// diferent area in the code or a consecutive run:
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel->where("id", 1)->select(["text"]); // will obtain data from cache without querying the database
// code ...

Custom cache name¶

If a custom cache name is set with the setCacheName method, or to the $cacheName protected property directly, then the Cache Model will include it in the name of the cached data, for simplified removal later.

Automatic removal on update¶

The Cache Base Model also automatically removes cached data on an update call if a custom cache name was set, but it will remove all the data stored with that particular custom cache name, for that model.

Example:

<?php
// user loads the page to view a forum post
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel
    ->setCacheName("post_id_1")
    ->where("id", 1)
    ->select(["text"]); // will execute the query and store it to cache
// code ...

// user edits the post
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel
    ->setCacheName("post_id_1")
    ->where("id", 1)
    ->update(["text" => "fixed post text"]); // will remove old cached data and update the data in the database
// code ...

// user loads the page to view a forum post again
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel
    ->setCacheName("post_id_1")
    ->where("id", 1)
    ->select(["text"]); // will execute the query and store it to cache
// code ...

Skipping cache¶

To skip caching the obtained data, or reading from the cache, even if the data exists the Cache Model provides a skipCache method that will disable cache for the next select call:

<?php
// code ...
$postModel = $app["loadDBModel.service"]("Post");
$postModel
    ->skipCache()
    ->where("id", 1)
    ->select(["text"]); // will obtain data from database and not store it to cache
// code ...