The examples in this article describe the database functions and usage of PHP encapsulation. Share it with everyone for your reference, the details are as follows:
The database module extracted from Thinkphp, I feel it is very easy to use
common.php：
<?PHP
/**
* 通用函数
*/
//包含配置文件
if (is_file("config.php")) {
C(include 'config.php');
}
if (!function_exists("__autoload")) {
function __autoload($class_name) {
require_once('classes/' . $class_name . '.class.php');
}
}
/**
* 数据库操作函数
* @return \mysqli
*/
function M() {
$db = new Model();
if (mysqli_connect_errno())
throw_exception(mysqli_connect_error());
return $db;
}
// 获取配置值
function C($name = null, $value = null) {
//静态全局变量，后面的使用取值都是在 $)config数组取
static $_config = array();
// 无参数时获取所有
if (empty($name))
return $_config;
// 优先执行设置获取或赋值
if (is_string($name)) {
if (!strpos($name, '.')) {
$name = strtolower($name);
if (is_null($value))
return isset($_config[$name]) ? $_config[$name] : null;
$_config[$name] = $value;
return;
}
// 二维数组设置和获取支持
$name = explode('.', $name);
$name[0] = strtolower($name[0]);
if (is_null($value))
return isset($_config[$name[0]][$name[1]]) ? $_config[$name[0]][$name[1]] : null;
$_config[$name[0]][$name[1]] = $value;
return;
}
// 批量设置
if (is_array($name)) {
return $_config = array_merge($_config, array_change_key_case($name));
}
return null; // 避免非法参数
}
function ajaxReturn($data = null, $message = "", $status) {
$ret = array();
$ret["data"] = $data;
$ret["message"] = $message;
$ret["status"] = $status;
echo json_encode($ret);
die();
}
//调试数组
function _dump($var) {
if (C("debug"))
dump($var);
}
// 浏览器友好的变量输出
function dump($var, $echo = true, $label = null, $strict = true) {
$label = ($label === null) ? '' : rtrim($label) . ' ';
if (!$strict) {
if (ini_get('html_errors')) {
$output = print_r($var, true);
$output = '<pre class="brush:php;toolbar:false">' . $label . htmlspecialchars($output, ENT_QUOTES) . '';
} else {
$output = $label . print_r($var, true);
}
} else {
ob_start();
var_dump($var);
$output = ob_get_clean();
if (!extension_loaded('xdebug')) {
$output = preg_replace("/\]\=\>\n(\s+)/m", '] => ', $output);
$output = '' . $label . htmlspecialchars($output, ENT_QUOTES) . ''; } } if ($echo) { echo($output); return null; } else return $output; } /** * 调试输出 * @param type $msg */ function _debug($msg) { if (C("debug")) echo "$msg
config.php ：
<?php /** * 数据库配置文件 */ $db = array( 'DB_TYPE' => 'mysql', 'DB_HOST' => '127.0.0.1', 'DB_NAME' => 'DB', 'DB_USER' => 'USER', 'DB_PWD' => 'PWD', 'DB_PORT' => '3306', ); return $db; ?>
Database model class Model.class.php, put it in the classes/ directory:
<?php
/**
* 数据库模型类
*/
class Model {
// 数据库连接ID 支持多个连接
protected $linkID = array();
// 当前数据库操作对象
protected $db = null;
// 当前查询ID
protected $queryID = null;
// 当前SQL指令
protected $queryStr = '';
// 是否已经连接数据库
protected $connected = false;
// 返回或者影响记录数
protected $numRows = 0;
// 返回字段数
protected $numCols = 0;
// 最近错误信息
protected $error = '';
public function __construct() {
$this->db = $this->connect();
}
/**
* 连接数据库方法
*/
public function connect($config = '', $linkNum = 0) {
if (!isset($this->linkID[$linkNum])) {
if (empty($config))
$config = array(
'username' => C('DB_USER'),
'password' => C('DB_PWD'),
'hostname' => C('DB_HOST'),
'hostport' => C('DB_PORT'),
'database' => C('DB_NAME')
);
$this->linkID[$linkNum] = new mysqli($config['hostname'], $config['username'], $config['password'], $config['database'], $config['hostport'] ? intval($config['hostport']) : 3306);
if (mysqli_connect_errno())
throw_exception(mysqli_connect_error());
$this->connected = true;
}
return $this->linkID[$linkNum];
}
/**
* 初始化数据库连接
*/
protected function initConnect() {
if (!$this->connected) {
$this->db = $this->connect();
}
}
/**
* 获得所有的查询数据
* @access private
* @param string $sql sql语句
* @return array
*/
public function select($sql) {
$this->initConnect();
if (!$this->db)
return false;
$query = $this->db->query($sql);
$list = array();
if (!$query)
return $list;
while ($rows = $query->fetch_assoc()) {
$list[] = $rows;
}
return $list;
}
/**
* 只查询一条数据
*/
public function find($sql) {
$resultSet = $this->select($sql);
if (false === $resultSet) {
return false;
}
if (empty($resultSet)) {// 查询结果为空
return null;
}
$data = $resultSet[0];
return $data;
}
/**
* 获取一条记录的某个字段值 , sql 由自己组织
* 例子： $model->getField("select id from user limit 1")
*/
public function getField($sql) {
$resultSet = $this->select($sql);
if (!empty($resultSet)) {
return reset($resultSet[0]);
}
}
/**
* 执行查询 返回数据集
*/
public function query($str) {
$this->initConnect();
if (!$this->db) {
if (C("debug"))
echo "connect to database error";
return false;
}
$this->queryStr = $str;
//释放前次的查询结果
if ($this->queryID)
$this->free();
$this->queryID = $this->db->query($str);
// 对存储过程改进
if ($this->db->more_results()) {
while (($res = $this->db->next_result()) != NULL) {
$res->free_result();
}
}
//$this->debug();
if (false === $this->queryID) {
echo $this->error();
return false;
} else {
$this->numRows = $this->queryID->num_rows;
$this->numCols = $this->queryID->field_count;
return $this->getAll();
}
}
/**
* 执行语句 ， 例如插入，更新操作
* @access public
* @param string $str sql指令
* @return integer
*/
public function execute($str) {
$this->initConnect();
if (!$this->db)
return false;
$this->queryStr = $str;
//释放前次的查询结果
if ($this->queryID)
$this->free();
$result = $this->db->query($str);
if (false === $result) {
$this->error();
return false;
} else {
$this->numRows = $this->db->affected_rows;
$this->lastInsID = $this->db->insert_id;
return $this->numRows;
}
}
/**
* 获得所有的查询数据
* @access private
* @param string $sql sql语句
* @return array
*/
private function getAll() {
//返回数据集
$result = array();
if ($this->numRows > 0) {
//返回数据集
for ($i = 0; $i < $this->numRows; $i++) {
$result[$i] = $this->queryID->fetch_assoc();
}
$this->queryID->data_seek(0);
}
return $result;
}
/**
* 返回最后插入的ID
*/
public function getLastInsID() {
return $this->db->insert_id;
}
// 返回最后执行的sql语句
public function _sql() {
return $this->queryStr;
}
/**
* 数据库错误信息
*/
public function error() {
$this->error = $this->db->errno . ':' . $this->db->error;
if ('' != $this->queryStr) {
$this->error .= "\n [ SQL语句 ] : " . $this->queryStr;
}
//trace($this->error, '', 'ERR');
return $this->error;
}
/**
* 释放查询结果
*/
public function free() {
$this->queryID->free_result();
$this->queryID = null;
}
/**
* 关闭数据库
*/
public function close() {
if ($this->db) {
$this->db->close();
}
$this->db = null;
}
/**
* 析构方法
*/
public function __destruct() {
if ($this->queryID) {
$this->free();
}
// 关闭连接
$this->close();
}
}Example:
#include "common.php"
function test(){
$model = M();
$sql = "select * from test";
$list = $model->query($sql);
_dump($list);
}I hope this article will be useful to everyone in PHP programming. helped.
For more PHP-encapsulated database functions and usage examples [refer to thinkPHP], please pay attention to the PHP Chinese website for related articles!
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