我为我正在处理的网站管理区域创建了一个时钟系统。但我想用一个类以更好的方式处理代码，所以我重新开始。到目前为止，我有2个班级。一个用于通过PDO处理数据库连接和对数据库的查询。
当启动时钟类（我必须从头开始构建）时，我正在接近，因为我在加载页面时不再收到错误。但是查询结果不正确，因为我应该为来自数据库的记录返回“true”而不是NULL。有人可以帮我理解我做错了什么。
我的数据库类是这样的（来自GitHub）......
/**
* DB - A simple database class
*
* @author Author: Vivek Wicky Aswal. (https://twitter.com/#!/VivekWickyAswal)
* @git https://github.com/indieteq/PHP-MySQL-PDO-Database-Class
* @version 0.2ab
*
*/
require("Log.class.php");
class DB
{
# @object, The PDO object
private $pdo;
# @object, PDO statement object
private $sQuery;
# @array, The database settings
private $settings;
# @bool , Connected to the database
private $bConnected = false;
# @object, Object for logging exceptions
private $log;
# @array, The parameters of the SQL query
private $parameters;
/**
* Default Constructor
*
* 1. Instantiate Log class.
* 2. Connect to database.
* 3. Creates the parameter array.
*/
public function __construct()
{
$this->log = new Log();
$this->Connect();
$this->parameters = array();
}
/**
* This method makes connection to the database.
*
* 1. Reads the database settings from a ini file.
* 2. Puts the ini content into the settings array.
* 3. Tries to connect to the database.
* 4. If connection failed, exception is displayed and a log file gets created.
*/
private function Connect()
{
$host = 'localhost';
$username = 'root';
$password = '';
$dbname = 'acro_1986';
//$this->settings = parse_ini_file("settings.ini.php");
$dsn = 'mysql:dbname='.$dbname.';host='.$host.'';
try
{
# Read settings from INI file, set UTF8
$this->pdo = new PDO($dsn, $username, $password, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
# We can now log any exceptions on Fatal error.
$this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
# Disable emulation of prepared statements, use REAL prepared statements instead.
$this->pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
# Connection succeeded, set the boolean to true.
$this->bConnected = true;
}
catch (PDOException $e)
{
# Write into log
echo $this->ExceptionLog($e->getMessage());
die();
}
}
/*
* You can use this little method if you want to close the PDO connection
*
*/
public function CloseConnection()
{
# Set the PDO object to null to close the connection
# http://www.php.net/manual/en/pdo.connections.php
$this->pdo = null;
}
/**
* Every method which needs to execute a SQL query uses this method.
*
* 1. If not connected, connect to the database.
* 2. Prepare Query.
* 3. Parameterize Query.
* 4. Execute Query.
* 5. On exception : Write Exception into the log + SQL query.
* 6. Reset the Parameters.
*/
private function Init($query,$parameters = "")
{
# Connect to database
if(!$this->bConnected) { $this->Connect(); }
try {
# Prepare query
$this->sQuery = $this->pdo->prepare($query);
# Add parameters to the parameter array
$this->bindMore($parameters);
# Bind parameters
if(!empty($this->parameters)) {
foreach($this->parameters as $param)
{
$parameters = explode("\x7F",$param);
$this->sQuery->bindParam($parameters[0],$parameters[1]);
}
}
# Execute SQL
$this->succes = $this->sQuery->execute();
}
catch(PDOException $e)
{
# Write into log and display Exception
echo $this->ExceptionLog($e->getMessage(), $query );
die();
}
# Reset the parameters
$this->parameters = array();
}
/**
* @void
*
* Add the parameter to the parameter array
* @param string $para
* @param string $value
*/
public function bind($para, $value)
{
$this->parameters[sizeof($this->parameters)] = ":" . $para . "\x7F" . utf8_encode($value);
}
/**
* @void
*
* Add more parameters to the parameter array
* @param array $parray
*/
public function bindMore($parray)
{
if(empty($this->parameters) && is_array($parray)) {
$columns = array_keys($parray);
foreach($columns as $i => &$column) {
$this->bind($column, $parray[$column]);
}
}
}
/**
* If the SQL query contains a SELECT or SHOW statement it returns an array containing all of the result set row
* If the SQL statement is a DELETE, INSERT, or UPDATE statement it returns the number of affected rows
*
* @param string $query
* @param array $params
* @param int $fetchmode
* @return mixed
*/
public function query($query,$params = null, $fetchmode = PDO::FETCH_ASSOC)
{
$query = trim($query);
$this->Init($query,$params);
$rawStatement = explode(" ", $query);
# Which SQL statement is used
$statement = strtolower($rawStatement[0]);
if ($statement === 'select' || $statement === 'show') {
return $this->sQuery->fetchAll($fetchmode);
}
elseif ( $statement === 'insert' || $statement === 'update' || $statement === 'delete' ) {
return $this->sQuery->rowCount();
}
else {
return NULL;
}
}
/**
* Returns the last inserted id.
* @return string
*/
public function lastInsertId() {
return $this->pdo->lastInsertId();
}
/**
* Returns an array which represents a column from the result set
*
* @param string $query
* @param array $params
* @return array
*/
public function column($query,$params = null)
{
$this->Init($query,$params);
$Columns = $this->sQuery->fetchAll(PDO::FETCH_NUM);
$column = null;
foreach($Columns as $cells) {
$column[] = $cells[0];
}
return $column;
}
/**
* Returns an array which represents a row from the result set
*
* @param string $query
* @param array $params
* @param int $fetchmode
* @return array
*/
public function row($query,$params = null,$fetchmode = PDO::FETCH_ASSOC)
{
$this->Init($query,$params);
return $this->sQuery->fetch($fetchmode);
}
/**
* Returns the value of one single field/column
*
* @param string $query
* @param array $params
* @return string
*/
public function single($query,$params = null)
{
$this->Init($query,$params);
return $this->sQuery->fetchColumn();
}
/**
* Writes the log and returns the exception
*
* @param string $message
* @param string $sql
* @return string
*/
private function ExceptionLog($message , $sql = "")
{
$exception = 'Unhandled Exception. <br />';
$exception .= $message;
$exception .= "<br /> You can find the error back in the log.";
if(!empty($sql)) {
# Add the Raw SQL to the Log
$message .= "\r\nRaw SQL : " . $sql;
}
# Write into log
$this->log->write($message);
return $exception;
}
}
我的时钟课......
class Timeclock {
public $user_id;
public function __construct($user_id) {
$this->user_id = $user_id ;
$this->db = new Db();
//$this->clocked_in = is_user_clocked_in($user_id);
}
public function is_user_clocked_in(){
$result = $this->db->query("SELECT * FROM timeclock WHERE user_id = :user_id AND time_out IS NULL", array("user_id"=>$this->user_id));
if ( count ( $result ) > 0 ){
return $result[0];
}else{
return null;
}
}
}
我这样称呼它......
if (isset($_SESSION['admin'])) {
$_user_id = $_SESSION['admin'][0]['user_id'];
// calls action and determines case
if (isset($_POST['action'])) {
$action = $_POST['action'];
} else if (isset($_GET['action'])) {
$action = $_GET['action'];
} else {
$action = 'home';
}
$action = strtolower($action);
switch ($action) {
case 'home':
$timeclock = new Timeclock($_user_id);
$user = new Timeclock($timeclock->user_id);
$clocked_in = $user->is_user_clocked_in();
include ('dashboard.php');
break;
}
}
此外，是否可以让类中的每个函数（一旦完成）一个接一个地运行并在顶部填充声明的变量（当然我已经添加了它们）所以我可以调用该类并让它运行一次？或者我是否必须根据需要单独调用每个功能？
答案 0 :(得分：0)
感谢您试图帮助@Ohgodwhy。 $ clocked_in返回一个数组，因为我要求它选择表中的所有列。所以当有结果时，它就是一个数组。我更改了函数的返回值以返回true而不是$ result [0]，因为我只需要知道用户是否已登录。我可能只是更改了查询以选择该列。在这之后，它工作得很好，直到我为表字段提供了一个值（使用户clocked_in）。然后我得到一个未定义的偏移量：0错误，因为当没有索引数组时我试图调用$ result [0]的值，因为查询显然返回数组（0）;我只是更改了计数以检查$ result是否存在。
如果有人遇到此，更新后的代码如下
Timeclock Class
class Timeclock {
public $user_id;
public function __construct($user_id) {
$this->user_id = $user_id ;
$this->db = new Db();
//$this->clocked_in = is_user_clocked_in($user_id);
}
public function is_user_clocked_in(){
$result = $this->db->query("SELECT * FROM timeclock WHERE user_id = :user_id AND time_out IS NULL", array("user_id"=>$this->user_id));
if ( count ($result) > 0 ){
return true;
}else{
return null;
}
}
}