Question

我想了解PDO人们已经说过简单而且最好的方式与数据库进行交互，但我发现它并不容易。可以帮忙吗？

Connection.php

<?php

class Connection {
    public function dbConnect() {
        return new PDO("mysql:host=localhost; dbname=lr", "root", "");
    }
}

?>

的index.php

<?php
require_once('pdo.php');
$obj = new Connection();

$obj->dbConnect();
echo 'hello';
?>

这很有效，但太简单了。什么是最好的方式？

我应该在自己的类中连接并将其扩展到我的其他类，还是应该使用全局变量进行连接？还是有另一种更好的方法吗？感谢

Answer 1

在某种程度上，这确实很容易使用全局变量会更容易。当然，你需要为include包含正确的文件名。

直接来自PDO tag wiki:

pdo.php

<?php
$dsn = "mysql:host=localhost;dbname=lr;charset=utf8";
$opt = array(
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
);
$pdo = new PDO($dsn,'root','', $opt);

的index.php

<?php
ini_set('display_errors',1);
error_reporting(E_ALL);

require_once('pdo.php');

$stm = $pdo->prepare("SELECT name FROM table WHERE id=?");
$stm->execute(array($_GET['id']));
$name = $stm->fetchColumn();
echo "Hello $name";

Answer 2

您只是创建一个连接，而不是告诉我们您要实现的目标。您想发布，更新，删除数据库中的内容还是什么？

我能做的最好，因为你没有要求任何东西是链接到一个网站，将尝试教你基本知识。我希望你之前使用过数据库。

http://net.tutsplus.com/tutorials/php/php-database-access-are-you-doing-it-correctly/

Answer 3

检查出来（https://gist.github.com/dirte/5331258）：

<?php
/*
 * PDO Database class
 *
 * Usage:
 * $db = Database::getInstance();
 * Return array of query results, normal statement: $results = $db->query("SELECT * FROM test WHERE name = 'Bob'");
 * Return array of query results, prepared statement (named params): $results = $db->query("SELECT * FROM test WHERE name = :name", array(":name" => "matthew"));
 * Return int of last insert result row id: $db->lastInsertId()
 * Return int of last query result row count: $db->lastQueryRowCount()
 */
class Database {

    /*
     * Instance of the database class
     *
     * @static Database $instance
     */
    private static $instance;

    /*
     * Database connection
     *
     * @access private
     * @var PDO $connection
     */
    private $connection;

    /*
     * Constructor
     *
     * @param $dsn The Data Source Name. eg, "mysql:dbname=testdb;host=127.0.0.1;port=3306"
     * @param $username
     * @param $password
     */
    private function __construct() {
        $this->connection = new PDO("mysql:dbname=".DBNAME.";host=".HOST.";port=".PORT, USER, PASS, array(
                                    PDO::ATTR_PERSISTENT => true,
                                    PDO::ATTR_TIMEOUT => DBTIMEOUT));
        if (empty($this->connection)) {
            trigger_error("Error #D001:", E_USER_ERROR);
            return false;
        }
        $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }

    /*
     * Gets an instance of the Database class
     *
     * @static $instance
     * @return Database An instance of the database singleton class
     */
    public static function getInstance() {
        if (empty(self::$instance)) {
            try {
                self::$instance = new Database();
            } catch (\PDOException $e) {
                trigger_error("Error #D002: ".$e->getMessage(), E_USER_ERROR);
            }
        }
        return self::$instance;
    }

    /*
     * Runs a query using the current connection to the database
     *
     * @param string query
     * @param array $args An array of arguments for the sanitization such as array(":name" => "foo")
     * @return array Containing all the remaining rows in the result set.
     */
    public function query($query, $args = false) {
        $tokens = array_map('trim',explode(" ",trim($query)));
        $query = str_replace(array("\r\n", "\r", "\t"), " ", $query);
        $query = str_replace('    ', ' ', $query);
        try {
            // Prepare results
            $results=false;

            // Allow for rollback if query fails
            $this->connection->beginTransaction();

            // Prepared statements
            $sth = $this->connection->prepare($query);

            // Execute prepared statement, with or without arguments
            if (empty($args)) {
                $sth->execute();
            } else {
                $multiple = false;
                foreach ($args as $arg) {
                    if (!is_array($arg)) { continue; }
                    $multiple = true;
                    break;
                }
                if ($multiple) {
                    $i=0;$j=count($args);
                    foreach ($args as $arg) {
                        foreach ($arg as $k=>$v) {
                            if ($v === "NULL") { $arg[$k] = NULL; }
                        }
                        $sth->execute($arg);
                        $i++;
                    }
                } else {
                    $i=0;$j=count($args);
                    foreach ($args as $a=>$arg) {
                        if ($arg === "NULL") {$args[$a] = NULL;}
                        $i++;
                    }
                    $sth->execute($args);
                }
            }
            // SELECT: Return array of data or false if 0 rows
            if ($tokens[0] == "SELECT") {
                $sth->setFetchMode(PDO::FETCH_ASSOC);
                $results = $sth->fetchAll();
            }
            // INSERT/UPDATE/REPLACE: Return number of affected rows / array of affected ids ?
            // Note: lastInsertId only works if ID col on table is auto_incremented
            elseif ($tokens[0] == "INSERT"
                    || $tokens[0] == "UPDATE"
                    || $tokens[0] == "REPLACE") {

                // If sessions table, assume key = return id
                $results = $this->connection->lastInsertId();
            }
            // Else: Return number of affected rows
            else {
                $results = $sth->rowCount();
            }
            // Attempt to commit changes, triggers exception if fails
            $this->connection->commit();

        // Rollback changes on failure
        } catch (\PDOException $e) {
            $msg = 'query(): ***** Caught Exception! Rolling back changes *****'.PHP_EOL.'<hr />Query:<pre>'.$query.'</pre>'.PHP_EOL.'<hr />Exception Message:<pre>'.$e->getMessage().'</pre><hr />'.PHP_EOL;
            $this->connection->rollBack();
            trigger_error($msg, E_USER_ERROR);
            return false;
        }

        return $results;
    }

    /*
     * Returns the last insert result row id
     *
     * @return int of last insert result row id
     */
    public function lastInsertId() {
        return $this->connection->lastInsertId();
    }

    /*
     * Returns the last query result row count
     *
     * @return int of last query result row count
     */
    public function lastQueryRowCount() {
        return $this->connection->lastQueryRowCount();
    }

}
?>

pdo连接类？

3 个答案: