我是 php/OOP 的初学者,对动态更改我的数据库连接有疑问。
这是我的主要.php的样子:
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Main extends CI_Controller {
function __construct()
{
parent::__construct();
/* Standard Libraries of codeigniter are required */
$this->load->database($connectdb);
$this->load->helper('url');
$this->load->library('grocery_CRUD');
}
public function index()
{
if ($_POST["username"] == "root")
{
$connectdb="default";
}
if ($_POST["username"] == "user1")
{
$connectdb="default1";
}
if ($_POST["username"] == "user2")
{
$connectdb="default2";
}
$connect = @mysql_connect("localhost", $_POST["username"], $_POST["password"]);//won't display the warning if any.
if (!$connect)
{
echo 'Server error. Please try again sometime. CON';
}else{
print("<a href='"http://v-admindb/ci/index.php/main/employees?username=".$_POST["username"]."'">Employees</a>");
echo "<br>";
print("<a href='"http://v-admindb/ci/index.php/main/visitors?username=".$_POST["username"]."'">Visitors</a>");
}//Just an example to ensure that we get into the function
// LOAD LIBRARIES
}
public function employees()
{
$this->grocery_crud->set_table('employees');
$output = $this->grocery_crud->render();
$this->_example_output($output);
}
public function visitors()
{
$this->grocery_crud->set_table('visitors');
$output = $this->grocery_crud->render();
$this->_example_output($output);
}
function _example_output($output = null)
{
$this->load->view('our_template.php',$output);
}
}
这是我database.php
:
$db['default']['hostname'] = 'localhost';
$db['default']['username'] = 'root';
$db['default']['password'] = 'root';
$db['default']['database'] = 'my_new_cms';
$db['default']['dbdriver'] = 'mysql';
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = '';
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;
//CONNECTION FOR user1
$db['default1']['hostname'] = 'localhost';
$db['default1']['username'] = 'user1';
$db['default1']['password'] = 'user1';
$db['default1']['database'] = 'my_new_cms';
$db['default1']['dbdriver'] = 'mysql';
$db['default1']['dbprefix'] = '';
$db['default1']['pconnect'] = TRUE;
$db['default1']['db_debug'] = TRUE;
$db['default1']['cache_on'] = FALSE;
$db['default1']['cachedir'] = '';
$db['default1']['char_set'] = 'utf8';
$db['default1']['dbcollat'] = 'utf8_general_ci';
$db['default1']['swap_pre'] = '';
$db['default1']['autoinit'] = TRUE;
$db['default1']['stricton'] = FALSE;
//CONNECTION FOR user2
$db['default2']['hostname'] = 'localhost';
$db['default2']['username'] = 'user2';
$db['default2']['password'] = 'user2';
$db['default2']['database'] = 'my_new_cms';
$db['default2']['dbdriver'] = 'mysql';
$db['default2']['dbprefix'] = '';
$db['default2']['pconnect'] = TRUE;
$db['default2']['db_debug'] = TRUE;
$db['default2']['cache_on'] = FALSE;
$db['default2']['cachedir'] = '';
$db['default2']['char_set'] = 'utf8';
$db['default2']['dbcollat'] = 'utf8_general_ci';
$db['default2']['swap_pre'] = '';
$db['default2']['autoinit'] = TRUE;
$db['default2']['stricton'] = FALSE;
当我尝试登录时,可能会出现此错误:
遇到 PHP 错误
严重性:通知
消息:未定义的变量:连接数据库
文件名:控制器/主.php
行号:12 遇到错误
尚未选择要连接到的数据库类型。
将$this->load->database($connectdb)
更改为default
、default1
或default2
使其正常工作。 如何将变量放入其中,以便连接参数根据登录者而变化?
希望有人能帮忙,谢谢!埃里克
您应该提供所有数据库信息application/config/database.php´
通常,您将设置默认数据库组,如下所示:
$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "";
$db['default']['database'] = "database_name";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "";
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = FALSE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = "";
$db['default']['char_set'] = "utf8";
$db['default']['dbcollat'] = "utf8_general_ci";
$db['default']['swap_pre'] = "";
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;
请注意,登录信息和设置在名为 $db['default']
的数组中提供。
然后,您可以在新数组中添加另一个数据库 - 我们称之为"otherdb"。
$db['anotherdb']['hostname'] = "localhost";
$db['anotherdb']['username'] = "root";
$db['anotherdb']['password'] = "";
$db['anotherdb']['database'] = "another_database_name";
$db['anotherdb']['dbdriver'] = "mysql";
$db['anotherdb']['dbprefix'] = "";
$db['anotherdb']['pconnect'] = TRUE;
$db['anotherdb']['db_debug'] = FALSE;
$db['anotherdb']['cache_on'] = FALSE;
$db['anotherdb']['cachedir'] = "";
$db['anotherdb']['char_set'] = "utf8";
$db['anotherdb']['dbcollat'] = "utf8_general_ci";
$db['anotherdb']['swap_pre'] = "";
$db['anotherdb']['autoinit'] = TRUE;
$db['anotherdb']['stricton'] = FALSE;
现在,如果您想使用第二个数据库,只需转到
$DB_another = $this->load->database('anotherdb', TRUE);
然后,而不是$this->db->foo()
,你会$DB_another->foo()
您可以像这样将其扩展到多个组
$DB2 = $this->load->database('anotherdb1', TRUE);
$DB3 = $this->load->database('anotherdb2', TRUE);
有关详细信息,请看这里:http://ellislab.com/codeigniter/user-guide/database/connecting.html
$this->load->database($connectdb);
问题就在这里,您将此变量加载到在索引函数中设置的构造函数中。
__constructor() 在 index() 之前触发,所以我想你应该做这样的事情:
class Main extends CI_Controller {
private $connectdb;
function __construct()
{
parent::__construct();
/* Standard Libraries of codeigniter are required */
$this->_setConnectdb();
$this->load->database($this->connectdb);
$this->load->helper('url');
$this->load->library('grocery_CRUD');
}
public function _setConnectdb()
{
if ( $_POST["username"] == "root" ) {
$this->connectdb = "default";
}
if ( $_POST["username"] == "user1" ) {
$this->connectdb = "default1";
}
if ( $_POST["username"] == "user2" ) {
$this->connectdb = "default2";
}