<?php
/*//pdo连接信息
$pdo=array("mysql:host=localhost;dbname=demo;charset=utf8","root","");
//开始连接数据库
$db = Mysql::newClass();
$db->pdoConnect($pdo);
$updateRow = array(
"user_id" => "2",
"meta_key" => "username"
);
//$db->select("wp_usermeta"); //发送sql
//$result=$db->selectOne(); //获取一条数据
//$db->selectCount(); //获取全部
//$db->update("wp_usermeta",$updateRow,"umeta_id=1"); //更新信息
//$db->insert("wp_usermeta",$updateRow); //插入数据
//echo $db->lastinsertid(); //获取插入后的id
//$db->delete("wp_usermeta","umeta_id>18"); //删除数据*/
class Mysql
{
private static $object;
private $PDO;
private $prepare;
/////单例模式 start
private function __construct()
{
}
public static function newClass()
{
if(!(self::$object instanceof self))
{
self::$object = new self;
}
return self::$object;
}
public function __clone(){
trigger_error('Clone is not allow!',E_USER_ERROR);
}
//////单例模式 end
//连接pdo
public function pdoConnect($address)
{
try{
$this->PDO = new PDO($address[0],$address[1],$address[2]);
$this->PDO->setAttribute(PDO::ATTR_PERSISTENT,true);
//设置抛出错误
$this->PDO->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
//设置当字符串为空时转换为sql的null
$this->PDO->setAttribute(PDO::ATTR_ORACLE_NULLS,true);
//由MySQL完成变量的转义处理
$this->PDO->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
}catch (PDOException $e)
{
$this->Msg("PDO连接错误信息：".$e->getMessage());
}
}
//错误提示
private function Msg($the_error=""){
$html="<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=UTF-8'/>
<title>mysql error</title>
</head>
<body>
<div style='width: 50%; height: 200px; border: 1px solid red; font-size: 12px;'>
$the_error
</div>
</body>
</html>
";
echo $html;
exit;
}
/*
*
* insert,delete,update操作
*
* */
public function insert($table,$row)
{
$sql=$this->sqlCreate("insert",$table,$row);
$result = $this->sqlExec($sql);
}
public function update($table,$row,$where)
{
$sql=$this->sqlCreate("update",$table,$row,$where);
$result = $this->sqlExec($sql);
}
public function delete($table,$where)
{
$sql=$this->sqlCreate("delete",$table,"",$where);
$result = $this->sqlExec($sql);
}
//服务与insert,update,delete，生成sql
private function sqlCreate($action,$table,$row="",$where="")
{
$actionArr = array(
"insert" => "insert into ",
"update" => "update ",
"delete" => "delete from "
);
$row = empty($row) ? "": $this->rowCreate($row);
$where = empty($where) ? "":" where ".$where;
$sql = $actionArr[$action].$table.$row.$where;
return $sql;
}
//拼成row
private function rowCreate($row)
{
$sql_row=" set";
foreach($row as $key=>$val)
{
$sql_row.=" ".$key."='".$val."',";
}
return trim($sql_row,",");
}
//执行sql，返还影响行数
private function sqlExec($sql)
{
try{
$result=$this->PDO->exec($sql);
}catch (PDOException $e)
{
$this->Msg($e->getMessage());
}
return $result;
}
//获取insert插入的id
public function lastinsertid()
{
return $this->PDO->lastinsertid();
}
/*
*
* select 部分
* */
public function select($table,$fields="", $where="",$orderby="", $sort="",$limit="")
{
$fields = empty($fields) ? "*":$fields;
$sqlSelect=$this->sqlCreateSelect($table,$fields,$where,$orderby,$sort,$limit);
$this->query($sqlSelect,$where);
}
//生成select sql
private function sqlCreateSelect($table,$fields="*", $where="",$orderby="", $sort="",$limit="")
{
$whereSql = empty($where)? " 1=1 ":$this->whereCreate($where);
$orderbySql = empty($orderby)? "":" order by ".$orderby." ".$sort;
$limitSql = empty($limit)? "":" limit ".$limit;
$sql="select $fields from $table where ".$whereSql.$orderbySql.$limitSql;
return $sql;
}
private function whereCreate($where)
{
$whereSql="";
foreach($where as $key=>$val)
{
$whereSql.=" ".$key."=:".$key." and";
}
return $whereSql." 1=1 ";
}
//执行select sql
private function query($sql,$where)
{
try{
$this->prepare = $this->PDO->prepare($sql);
}catch (PDOException $e)
{
$this->Msg("预处理sql出错信息:".$e->getMessage()."<br>sql:(".$sql.")");
}
empty($where)? "":$this->bind($where);
$this->prepare ->execute();
}
private function bind($where)
{
foreach($where as $key=>$val)
{
$this->prepare->bindValue(":".$key,$val);
}
}
/*select获取数据*/
//获取一条
public function selectOne()
{
$result=$this->prepare->fetch(PDO::FETCH_ASSOC);
return $result;
}
//获取全部数据
public function selectAll()
{
$result=$this->prepare->fetchAll(PDO::FETCH_ASSOC);
return $result;
}
//获取查询记录数
public function selectCount()
{
$total = $this->prepare->rowCount();
return $total;
}
}
