tboronczyk/alistair

pedagogical database wrapper and mvc-model starter kit

Alistair

Alistair is a simple SQL database wrapper written for pedagogical purposes. It demonstrates how one can encapsulate common database operations and organize raw queries into a basis for MVC models/repositories.

Classes

DbAccess

The DbAccess class provides methods for executing queries against an SQL database.

Methods defined by DbAccessInterface:

• query - execute a query
• queryRows - execute a query and return result rows
• queryRow - execute a query and return a single result row
• queryValue - execute a query and return a single value
• getPdo - get the underlying PDO connection object

Example Usage

<?php
use Boronczyk\Alistair\DbAccess;

class Users
{
    public function __construct(
        protected DbAccess $db
    ) {
    }

    public function getById(int $id): array
    {
        return $this->db->queryRow(
            'SELECT id, username, email FROM users WHERE id = ?',
            [$id]
        );
    }
}

$db = new DbAccess(new \PDO(...));

$users = new Users($db);
$user = $users->getById(42);

CrudModel

CrudModel is an abstract class that provides basic methods for CRUD operations (create, retrieve, update, delete). Implementations must implement the columns method returning an array of known column names for the table.

Implementations may override the table method returning the name of the table (the base implementation derives the table name from the class's name). Implementations may also override the requiredColumns method returning an array of column names required to perform create and update operations if the list is different from that returned by column.

Methods defined by CrudModelInterface:

• table - return the table name
• columns - return a list of known column names
• count - return the number of records in the table
• get - return records, supports column filtering and pagination
• getById - return a record by ID, supports column filtering
• create - create a new record
• update - update an existing record
• delete - delete an existing record

Example Usage

<?php
use Boronczyk\Alistair\DbAccess;
use Boronczyk\Alistair\CrudModel;

class Users extends CrudModel
{
    // implementation required by abstract class
    public function columns(): array {
        return [
            'username',
            'email'
        ];
    }
}

$db = new DbAccess(new \PDO(...));

$users = new Users($db);
$user = $users->getById(42);