gistfile1.php

<?php
/*
 * File Name: Database.php
 * Date: November 18, 2008
 * Author: Angelo Rodrigues
 * Description: Contains database connection, result
 *              Management functions, input validation
 *
 *              All functions return true if completed
 *              successfully and false if an error
 *              occurred
 *
 */
class Database
{

    /*
     * Edit the following variables
     */
    private $db_host = 'localhost';     // Database Host
    private $db_user = 'root';          // Username
    private $db_pass = 'root';          // Password
    private $db_name = 'blog';          // Database
    /*
     * End edit
     */

    private $con = false;               // Checks to see if the connection is active
    private $result = array();          // Results that are returned from the query

    /*
     * Connects to the database, only one connection
     * allowed
     */
    public function connect()
    {
        if($this->con)
            return true;

        $myconn = @mysql_connect($this->db_host,$this->db_user,$this->db_pass);

        if( ! $myconn)
            return false;

        $seldb = @mysql_select_db($this->db_name, $myconn);
        
        $this->con = (bool) $seldb;
        return (bool) $seldb;
    }

    /*
    * Changes the new database, sets all current results
    * to null
    */
    public function setDatabase($name)
    {
        if( ! $this->con || ! mysql_close())
            return false;

        $this->con = false;
        $this->results = null;
        $this->db_name = $name;
        $this->connect();
    }

    /*
    * Checks to see if the table exists when performing
    * queries
    */
    private function tableExists($table)
    {
        return mysql_num_rows(mysql_query("SHOW TABLES FROM {$this->db_name} LIKE \"{$table}\"") == 1;
    }

    /*
    * Selects information from the database.
    * Required: table (the name of the table)
    * Optional: rows (the columns requested, separated by commas)
    *           where (column = value as a string)
    *           order (column DIRECTION as a string)
    */
    public function select($table, $rows = '*', $where = null, $order = null)
    {
        $where = $where ? " WHERE {$where}" : '';
        $order = $order ? " ORDER BY {$order}" : '';

        $q = "SELECT {$rows} FROM {$table}{$where}{$order}";

        $query = @mysql_query($q);
        
        if( ! $query)
            return false;

        $this->result = array();

        while($row = mysql_fetch_assoc($query))
            $this->result[] = $row;

        $this->numResults = count($this->result);

        return true;
    }

    /*
    * Insert values into the table
    * Required: table (the name of the table)
    *           values (the values to be inserted)
    * Optional: rows (if values don't match the number of rows)
    */
    public function insert($table,$values,$rows = null)
    {
        if( ! $this->tableExists($table))
            return false;

        $insert = 'INSERT INTO '.$table;

        if($rows != null)
            $insert .= ' ('.$rows.')';

        $values = array_map(array($this, 'quote_strings'), $values);

        $values = implode(', ', $values);
        $insert .= ' VALUES ('.$values.')';

        return (bool) mysql_query($insert);
    }

    /*
    * Deletes table or records where condition is true
    * Required: table (the name of the table)
    * Optional: where (condition [column =  value])
    */
    public function delete($table, $where = null)
    {
        if( ! $this->tableExists($table))
            return false;

        $delete = is_null($where) ? "DELETE {$table}" : "DELETE FROM {$table} WHERE {$where}";

        return (bool) @mysql_query($delete);
    }

    /*
     * Updates the database with the values sent
     * Required: table (the name of the table to be updated
     *           rows (the rows/values in a key/value array
     *           where (the row/condition in an array (row,condition) )
     */
    public function update($table,$rows,$where)
    {
        if( ! $this->tableExists($table))
            return false;

        $wheres = array();
        foreach($where as $column => $criteria)
            $wheres[] = "{$column} = \"{$criteria}\"";

        $where = implode(' AND ', $wheres);

        $values = array();
        foreach($rows as $column => $value)
            $values[] = $column.' = '.$this->quote_strings($value);
        $values = implode(', ', $values);

        return (bool) mysql_query("UPDATE {$table} SET {$values} WHERE {$where}");
    }

    protected function quote_strings($value) {
        return is_string($value) ? "\"{$value}\"" : $value;
    }

    /*
    * Returns the result set
    */
    public function getResult()
    {
        return $this->result;
    }
}