<?php
class lib_mysqli {
protected $mysqli;//mysqli实例对象
public $sql;//sql语句
protected $rs;//结果集
protected $query_num= 0;//执行次数
protected $fetch_mode= MYSQLI_ASSOC;//获取模式
protected $cache;//缓存类对象
protected $reload = false;//是否重新载入
protected $cache_mark = true;//缓存标记
//构造函数：主要用来返回一个mysqli对象
public function __construct($dbhost, $dbuser, $dbpass, $dbname, $dbport) {
$this->mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname, $dbport);
if(mysqli_connect_errno()) {
$this->mysqli = false;
echo '<h2>'.mysqli_connect_error().'</h2>';
die();
} else {
$this->mysqli->set_charset("utf8");
}
}
//缓存类对象：文件缓存、memcache键值对缓存
public function cache_obj($cache) {
$this->cache= $cache;
}
//析构函数：主要用来释放结果集和关闭数据库连接
public function __destruct() {
$this->free();
$this->close();
}
//释放结果集所占资源
protected function free() {
@$this->rs->free();
}
//关闭数据库连接
protected function close() {
$this->mysqli->close();
}
//获取结果集
protected function fetch() {
return $this->rs->fetch_array($this->fetch_mode);
}
//获取查询的sql语句
protected function get_query_sql($sql, $limit = null) {
if (@preg_match("/[0-9]+(,[ ]?[0-9]+)?/is", $limit) && !preg_match("/ LIMIT [0-9]+(,[ ]?[0-9]+)?$/is", $sql)) {
$sql .= " LIMIT " . $limit;
}
return $sql;
}
//从缓存中获取数据
protected function get_cache($sql,$method) {
$cache_file = md5($sql.$method);
$res = $this->cache->get($cache_file);
if(!$res) {//如果缓存文件过期或不存在的话，返回false；如果缓存文件存在且未过期的话，则返回缓存数据
$res = $this->$method($sql);//先从缓存中取数据，如果缓存中没数据，则从数据库中取数据
if($res && $this->cache_mark && !$this->reload) {
$this->cache->set($cache_file, $res);//如果缓存文件过期或不存在的话，将重新将从数据库中查询的数据放入缓存文件
}
}
return $res;
}
//获取查询次数
public function query_num() {
return $this->query_num;
}
//执行sql语句查询
public function query($sql, $limit = null) {
$sql = $this->get_query_sql($sql, $limit);
$this->sql[] = $sql;
$this->rs = $this->mysqli->query($sql);
if (!$this->rs) {
echo "<p>error: ".$this->mysqli->error."</p>";
echo "<p>sql: ".$sql."</p>";
die();
} else {
$this->query_num++;
return $this->rs;
}
}
//返回单条记录的单个字段值
public function get_one($sql) {
$this->query($sql, 1);
$this->fetch_mode = MYSQLI_NUM;
$row = $this->fetch();
$this->free();
return $row[0];
}
//缓存单个字段
public function cache_one($sql, $reload = false) {
$this->reload= $reload;
$sql = $this->get_query_sql($sql, 1);
return $this->get_cache($sql, 'get_one');
}
//获取单条记录
public function get_row($sql, $fetch_mode = MYSQLI_ASSOC) {
$this->query($sql, 1);
$this->fetch_mode = $fetch_mode;
$row = $this->fetch();
$this->free();
return $row;
}
//缓存行
public function cache_row($sql, $reload = false) {
$this->reload= $reload;
$sql = $this->get_query_sql($sql, 1);
return $this->get_cache($sql, 'get_row');
}
//返回所有的结果集
public function get_all($sql, $limit = null, $fetch_mode = MYSQLI_ASSOC) {
$this->query($sql, $limit);
$all_rows = array();
$this->fetch_mode = $fetch_mode;
while($rows = $this->fetch()) {
$all_rows[] = $rows;
}
$this->free();
return $all_rows;
}
//缓存all
public function cache_all($sql, $reload = false, $limit = null) {
$this->reload= $reload;
$sql = $this->get_query_sql($sql, $limit);
return $this->get_cache($sql, 'get_all');
}
//返回前一次mysql操作所影响的记录行数
public function affected_rows() {
return $this->mysqli->affected_rows;
}
/**
* 获取插入语句
*
* @param string $tbl_name 表名
* @param array $info 数据
*/
public function get_insert_db_sql($tbl_name,$info)
{
//首先判断是否为数组，再判断数组是否为空
if(is_array($info)&&!empty($info))
{
$i = 0;
foreach($info as $key=>$val)
{
$fields[$i] = $key;//将所有的键名放到一个$fields[]数组中
$values[$i] = $val;//将所有的值放到一个$values[]数组中
$i++;
}
$s_fields = "(".implode(",",$fields).")";
$s_values = "('".implode("','",$values)."')";
$sql = "INSERT INTO
$tbl_name
$s_fields
VALUES
$s_values";
Return $sql;
}
else
{
Return false;
}
}
/**
* 获取替换语句:replace into是insert into的增强版
* 区别：replace into跟insert功能类似，不同点在于：replace into 首先尝试插入数据到表中，如果发现表中
已经有此行数据(根据主键或唯一索引判断)，则先删除此行数据，然后插入新的数据，否则直接插入新数据
* @param string $tbl_name 表名
* @param array $info 数据
*/
public function get_replace_db_sql($tbl_name,$info)
{
if(is_array($info)&&!empty($info))
{
$i = 0;
foreach($info as $key=>$val)
{
$fields[$i] = $key;
$values[$i] = $val;
$i++;
}
$s_fields = "(".implode(",",$fields).")";
$s_values = "('".implode("','",$values)."')";
$sql = "REPLACE INTO
$tbl_name
$s_fields
VALUES
$s_values";
Return $sql;
}
else
{
Return false;
}
}
/**
* 获取更新SQL语句
*
* @param string $tbl_name 表名
* @param array $info 数据
* @param array $condition 条件
*/
public function get_update_db_sql($tbl_name,$info,$condition)
{
$i = 0;
$data = '';
if(is_array($info)&&!empty($info))
{
foreach( $info as $key=>$val )
{
if(isset($val))
{
$val = $val;
if($i==0&&$val!==null)
{
$data = $key."='".$val."'";//第一次：如，update 表名 set username='admin'
}
else
{
$data .= ",".$key." = '".$val."'";//非第一次：如， ，password='123'
}
$i++;
}
}
$sql = "UPDATE ".$tbl_name." SET ".$data." WHERE ".$condition;
return $sql;
}
else
{
Return false;
}
}
/**
* 取得数据库最后一个插入ID
*
* @return int
*/
public function last_id() {
return mysqli_insert_id($this->mysqli);
}
public function real_get($sql, $fetch_mode = MYSQLI_ASSOC) {
$this->query($sql);
$this->fetch_mode = $fetch_mode;
$row = $this->fetch();
$this->free();
return $row;
}
}在model中使用：
$tbl_product = TBL_PRE . "products"; $tbl_goods = TBL_PRE . "goods"; $tbl_brand = TBL_PRE . "goods_brand"; $tbl_category = TBL_PRE . "goods_category"; $tbl_type = TBL_PRE . "goods_type"; $tbl_spec = TBL_PRE ."goods_specification"; $sql = " SELECT a.*, b.brand_name, b.brand_name_second,b.brand_logo,b.brand_simple_intro, b.url_path,c.category_name,c.url_path AS cate_url_path, sp.spec_name, sp.spec_memo FROM (SELECT g.*,p.product_id, p.bn, p.bar_code, p.color_id, p.color_text,p.small_list_page_product_pic_default, p.small_list_page_product_pic_replace,p.is_new, p.is_promotion,p.is_newstyle,p.is_limit,p.is_classic,p.is_new_spring,p.act_id, p.product_name, p.price as product_price, p.market_price as product_market_price, p.intro, p.editor_intro,p.size_image_path, p.size_intro, p.video_path, p.size_image_name, p.status as pstatus, p.is_stop as pisstop FROM $tbl_product p LEFT JOIN $tbl_goods g ON p.goods_id = g.goods_id WHERE p.product_id = $id $_filter) a LEFT JOIN $tbl_brand b ON a.brand_id = b.brand_id LEFT JOIN $tbl_category c ON a.category_id = c.category_id LEFT JOIN $tbl_spec sp ON a.spec_id = sp.spec_id"; $result['base'] = $this->db->cache_row($sql);
