sealandia-framework/framework/database.php

<?php

namespace Framework;

use PDO;

Class Database{
    private $pdo;
    private $type;
    private $table;
    private $columns;
    private $where;
    private $limit;
    private $query;

    /**
     * Constructor method to initialize the PDO instance
     */

    public function __construct(){
        $this->pdo = new PDO('mysql:host=' . $db_config['host'] . ';dbname=' . $db_config['database'] . ';charset=utf8mb4', $db_config['username'], $db_config['password']);
    }

    /**
     * Method to start a SELECT query and specify columns
     */

    public function select($columns = "*"){
        $this->type = "SELECT";
        $this->columns = $columns;
    }

    /**
     * Method to specify the table to query
     */

    public function from($table){
        $this->table = $table;
    }

    /**
     * Method to add a WHERE clause to the query
     */

    public function where($key, $value){
        $this->where = array($key, $value);
    }

    /**
     * Method to add additional conditions to the WHERE clause
     */

    public function andWhere($key, $value){
        if(!$this->where) $this->where = array();
        $this->where[$key] = $value;
    }

    /**
     * Method to add a LIMIT clause to the query
     */

    public function limit($number){
        $this->limit = $number;
    }

    /**
     * Method to execute the query and return all results
     */

    public function all(){
        $this->query = $this->type . ' ' . $this->columns . ' FROM ' . $this->table;

        /**
         * Check if a WHERE clause is set, if so, then append it to the query.
         * Then construct WHERE conditions using placeholders for prepared statements and
         * join the WHERE conditions with AND and append them to the query
         */
        
        if(!empty($this->where)){
            $whereClauses = [];
            foreach($this->where as $condition){
                $whereClauses[] = $condition[0] . ' = :"' . $condition[0];
            }
            $this->query .= ' WHERE ' . implode(' AND ', $whereClauses);
        }

        if(!empty($this->limit)){
            $this->query .= ' LIMIT ' . $this->limit;
        }

        $results = $this->pdo->prepare($Query);

        /**
         * Bind the values from the WHERE clause to the prepared statement
         */
        
        foreach($this->where as $condition){
            $results->bindValue(':' . $condition[0], $condition[1]);
        }
        
        $results->execute();
		return $results->fetchAll();
    }

    /**
     * Method to execute the query and return a single result
     */

    public function one(){
        $this->query = $this->type . ' ' . $this->columns . ' FROM ' . $this->table;

        /**
         * Check if a WHERE clause is set, if so, then append it to the query.
         * Then construct WHERE conditions using placeholders for prepared statements and
         * join the WHERE conditions with AND and append them to the query
         */
        
        if(!empty($this->where)){
            $whereClauses = [];
            foreach($this->where as $condition){
                $whereClauses[] = $condition[0] . ' = :"' . $condition[0];
            }
            $this->query .= ' WHERE ' . implode(' AND ', $whereClauses);
        }
        
        $this->query .= " LIMIT 1";
        $results = $this->pdo->prepare($Query);

        /**
         * Bind the values from the WHERE clause to the prepared statement
         */

        foreach($this->where as $condition){
            $results->bindValue(':' . $condition[0], $condition[1]);
        }

        $results->execute();
		return $results->fetch();
    }
}

// Database::select(id, name)->from('tablename')->all()
// Database::select(id, name)->from('tablename')->limit(100)->all()
// Database::select()->from('tablename')->where('id', 3)->one()

?>