<?phpclass Db{//私有静态属性存储实例化对象自身private static $instance;//存储PDO类的实例化private $pdo;//PDOStatement类private $stmt;//禁止外部实例化对象,链接数据库private function __construct($config,$port,$charset){try{$this->pdo = new PDO('mysql:host='.$config['host'].';dbname='.$config['dbname'].';charset='.$charset.';port='.$port.'',$config['user'],$config['password']);//开始事务回滚的错误警告$this->pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);}catch(PDOException $e){echo 'msyql error: '.$e->getMessage();}}//外部实例化public static function getInstance($config,$port=3306,$charset='utf8'){if(!self::$instance instanceof Db){self::$instance = new self($config,$port,$charset);}return self::$instance;}//插入数据public function insertData($table,$data){//拼接插入的数据库字段名$columns = implode(',',array_keys($data));//凭借插入的数据$values = ':'.implode(',:',array_keys($data));$sql = "insert into $table ($columns) values ($values)";//处理date数据格式$newdata = $this->doData($data);//预处理sql,执行添加数据操作$this->doSql($sql,$newdata);//成功执行后返回插入数据的id,失败返回错误信息if($this->stmt->errorCode()==00000){return $this->pdo->lastInsertId();}else{return $this->stmt->errorInfo()[2];}}//更新数据public function updateData($table,$data,$where){//检查需要更新的数据是否存在if(!$this->getOne($table,array_keys($data)[0],$where)){echo '需要更新的数据不存在';return false;}//检查传入的数据并且拼接成字符串if(is_array($data)){$columns = '';foreach($data as $k=>$v){$columns.= $k.'=:'.$k.',';}$columns=rtrim($columns,',');}//sql语句$sql = "UPDATE $table SET $columns WHERE ".$where;//传入的数组处理成pdo定的数据格式[':user_name'=>'lisi',':user_age'=>39]$newdata = $this->doData($data);//预处理sql,执行添加数据操作$this->doSql($sql,$newdata);//没有错误返回1,有错误返回错误信息if($this->stmt->errorCode()==00000){return 1;}else{return $this->stmt->errorInfo()[2];}}//查询一条数据public function getOne($table,$fields,$where){//检查传入的字段是否是数组if(is_array($fields)){if(count($fields)>1){$columns=implode(',',$fields);}else{$columns=$fields[0];} }else{$columns = $fields;}//查询语句$sql = "SELECT $columns FROM $table WHERE ".$where.' LIMIT 1';//预处理sql,执行添加数据操作$this->doSql($sql);//获得查询的结果集$res = $this->stmt->fetch(PDO::FETCH_ASSOC);//如果没有错误则返回查询的结果集,否则返回错误信息if($this->stmt->errorCode()==00000){return $res;}else{return $this->stmt->errorInfo()[2];} }//查询多条数据public function getAll($table,$fields,$where=1){//检查传入的字段是否是数组if(is_array($fields)){if(count($fields)>1){$columns=implode(',',$fields);}else{$columns=$fields[0];} }else{$columns = $fields;}//查询语句$sql = "SELECT $columns FROM $table WHERE ".$where;//预处理sql,执行添加数据操作$this->doSql($sql);//获得查询的结果集$res = $this->stmt->fetchALL(PDO::FETCH_ASSOC);//如果没有错误则返回查询的结果集,否则返回错误信息if($this->stmt->errorCode()==00000){return $res;}else{return $this->stmt->errorInfo()[2];} }//删除数据public function delData($table,$where){//检查需要更新的数据是否存在if(!$this->getOne($table,['*'],$where)){echo '需要删除的数据不存在';return false;}if(!$where){echo '请添加删除条件';return false;}$sql = "DELETE FROM $table WHERE ".$where;//预处理sql,执行添加数据操作$this->doSql($sql);//如果没有错误则返回查询的结果集,否则返回错误信息if($this->stmt->errorCode()==00000){return 1;}else{return $this->stmt->errorInfo()[2];}}//处理传入的数据private function doData($data){foreach($data as $k=>$v){$newk = ':'.$k;$newdata[$newk]=$v;}return $newdata;}//执行sql操作function doSql($sql,$data=null){//预处理sql$this->stmt=$this->pdo->prepare($sql);//执行添加数据操作$this->stmt->execute($data);}//禁止外部克隆private function __clone(){}}
$config = ['host'=>'127.0.0.1','dbname'=>'shop','user'=>'root','password'=>'root'];
$db = Db::getInstance($config,3306,'utf8');//插入数据
$table= 'user';
$data=['user_name'=>'sunliang','user_age'=>28,'sex'=>1,'email'=>'323424958@126.com','password'=>md5(123456),'money'=>544545.34];
echo $db->insertData($table,$data);
// $sql = 'insert into (username,password) values (:username,password)';
// $stmt = $db->prepare($sql);
// $data = [':username'=>'lisi',':password'=>123456];
// $stmt->execute($data);//修改数据
// $table = 'user';
// $data=['user_name'=>'sunliang','user_age'=>28,'email'=>'323424958@qq.com'];
// $sql = "update user set user_name=:username,user_age=:user_age,email=:email where id = 1";
// echo $db->updateData($table,$data,'id=18');
// $stmt = $db->prepare($sql);
// $stmt->execute($data);//查询一条数据
// $table = 'user';
// $fields= ['user_name','id'];
// $sql = 'select user_name,email from user where id = 1';
// print_r($db->getOne($table,$fields,'id=2'));//查询多条数据
// $table = 'user';
// $fields= ['user_name','id'];
// $sql = 'select user_name,email from user where id = 1';
// print_r($db->getAll($table,$fields));//删除数据
// $table = 'user';
// echo $db->delData($table,'id=16');
简单的数据库类
转载于:https://blog.51cto.com/woaijorden/2153207