Question

您好，目前我已经下载了一个PHP PDO类，它看起来像这样：

class db extends PDO {
    private $error;
    private $sql;
    private $bind;
    private $errorCallbackFunction;
    private $errorMsgFormat;

    public function __construct($dsn, $user="", $passwd="") {
        $options = array(
            PDO::ATTR_PERSISTENT => true, 
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
        );

        try {
            parent::__construct($dsn, $user, $passwd, $options);
        } catch (PDOException $e) {
            $this->error = $e->getMessage();
        }
    }

    private function debug() {
        if(!empty($this->errorCallbackFunction)) {
            $error = array("Error" => $this->error);
            if(!empty($this->sql))
                $error["SQL Statement"] = $this->sql;
            if(!empty($this->bind))
                $error["Bind Parameters"] = trim(print_r($this->bind, true));

            $backtrace = debug_backtrace();
            if(!empty($backtrace)) {
                foreach($backtrace as $info) {
                    if($info["file"] != __FILE__)
                        $error["Backtrace"] = $info["file"] . " at line " . $info["line"];  
                }       
            }

            $msg = "";
            if($this->errorMsgFormat == "html") {
                if(!empty($error["Bind Parameters"]))
                    $error["Bind Parameters"] = "<pre>" . $error["Bind Parameters"] . "</pre>";
                $css = trim(file_get_contents(dirname(__FILE__) . "/error.css"));
                $msg .= '<style type="text/css">' . "\n" . $css . "\n</style>";
                $msg .= "\n" . '<div class="db-error">' . "\n\t<h3>SQL Error</h3>";
                foreach($error as $key => $val)
                    $msg .= "\n\t<label>" . $key . ":</label>" . $val;
                $msg .= "\n\t</div>\n</div>";
            }
            elseif($this->errorMsgFormat == "text") {
                $msg .= "SQL Error\n" . str_repeat("-", 50);
                foreach($error as $key => $val)
                    $msg .= "\n\n$key:\n$val";
            }

            $func = $this->errorCallbackFunction;
            $func($msg);
        }
    }

    public function delete($table, $where, $bind="") {
        $sql = "DELETE FROM " . $table . " WHERE " . $where . ";";
        $this->run($sql, $bind);
    }

    private function filter($table, $info) {
        $driver = $this->getAttribute(PDO::ATTR_DRIVER_NAME);
        if($driver == 'sqlite') {
            $sql = "PRAGMA table_info('" . $table . "');";
            $key = "name";
        }
        elseif($driver == 'mysql') {
            $sql = "DESCRIBE " . $table . ";";
            $key = "Field";
        }
        else {  
            $sql = "SELECT column_name FROM information_schema.columns WHERE table_name = '" . $table . "';";
            $key = "column_name";
        }   

        if(false !== ($list = $this->run($sql))) {
            $fields = array();
            foreach($list as $record)
                $fields[] = $record[$key];
            return array_values(array_intersect($fields, array_keys($info)));
        }
        return array();
    }

    private function cleanup($bind) {
        if(!is_array($bind)) {
            if(!empty($bind))
                $bind = array($bind);
            else
                $bind = array();
        }
        return $bind;
    }

    public function insert($table, $info) {
        $fields = $this->filter($table, $info);
        $sql = "INSERT INTO " . $table . " (" . implode($fields, ", ") . ") VALUES (:" . implode($fields, ", :") . ");";
        $bind = array();
        foreach($fields as $field)
            $bind[":$field"] = $info[$field];
        return $this->run($sql, $bind);
    }

    public function run($sql, $bind="") {
        $this->sql = trim($sql);
        $this->bind = $this->cleanup($bind);
        $this->error = "";

        try {
            $pdostmt = $this->prepare($this->sql);
            if($pdostmt->execute($this->bind) !== false) {
                if(preg_match("/^(" . implode("|", array("select", "describe", "pragma")) . ") /i", $this->sql))
                    return $pdostmt->fetchAll(PDO::FETCH_ASSOC);
                elseif(preg_match("/^(" . implode("|", array("delete", "insert", "update")) . ") /i", $this->sql))
                    return $pdostmt->rowCount();
            }   
        } catch (PDOException $e) {
            $this->error = $e->getMessage();    
            $this->debug();
            return false;
        }
    }

    public function select($table, $where="", $bind="", $fields="*") {
        $sql = "SELECT " . $fields . " FROM " . $table;
        if(!empty($where))
            $sql .= " WHERE " . $where;
        $sql .= ";";
        return $this->run($sql, $bind);
    }

    public function setErrorCallbackFunction($errorCallbackFunction, $errorMsgFormat="html") {
        //Variable functions for won't work with language constructs such as echo and print, so these are replaced with print_r.
        if(in_array(strtolower($errorCallbackFunction), array("echo", "print")))
            $errorCallbackFunction = "print_r";

        if(function_exists($errorCallbackFunction)) {
            $this->errorCallbackFunction = $errorCallbackFunction;  
            if(!in_array(strtolower($errorMsgFormat), array("html", "text")))
                $errorMsgFormat = "html";
            $this->errorMsgFormat = $errorMsgFormat;    
        }   
    }

    public function update($table, $info, $where, $bind="") {
        $fields = $this->filter($table, $info);
        $fieldSize = sizeof($fields);

        $sql = "UPDATE " . $table . " SET ";
        for($f = 0; $f < $fieldSize; ++$f) {
            if($f > 0)
                $sql .= ", ";
            $sql .= $fields[$f] . " = :update_" . $fields[$f]; 
        }
        $sql .= " WHERE " . $where . ";";

        $bind = $this->cleanup($bind);
        foreach($fields as $field)
            $bind[":update_$field"] = $info[$field];

        return $this->run($sql, $bind);
    }
}

每次我使用它时，我都需要将它包含在include("class.db.php");这样的页面中，并提供我的数据源名称，用户名和密码，如$db = new db("mysql:host=localhost;dbname=db_information", "root", "");。我想做的不是总是提供那条线，我想把它包含在我的课堂上。我所做的是将该行放在类的最后部分，但它看起来很脏。我怎样才能把它包含在我的课堂上？

Answer 1

将构造函数更改为：

public function __construct($dsn='', $user='', $passwd='') {
    $options = array(
        PDO::ATTR_PERSISTENT => true, 
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
    );

    if (empty($dsn)) {
        $dsn = 'mysql:host=localhost;dbname=db_information';
    }

    if (empty($user)) {
        $user = 'root';
    }

    try {
        parent::__construct($dsn, $user, $passwd, $options);
    } catch (PDOException $e) {
        $this->error = $e->getMessage();
    }
}

这样你仍然可以提供另一个连接，然后是默认连接。

Answer 2

你不应该把它添加到你的班级。如果您真的想在不输入凭据的情况下自动连接，那么您应该做的最好的事情就是创建配置文件并将其包含在需要连接的每个页面的开头。

PHP PDO类连接

2 个答案: