PHP DB 数据库连接类
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<?php // 数据库连接类 class DB{ //私有的属性 private static $dbcon=false; private $host; private $port; private $user; private $pass; private $db; private $charset; private $link; //私有的构造方法 private function __construct(){ $this->host = 'localhost'; $this->port = '3306'; $this->user = 'root'; $this->pass = 'root'; $this->db = 'imooc'; $this->charset= 'utf8'; //连接数据库 $this->db_connect(); //选择数据库 $this->db_usedb(); //设置字符集 $this->db_charset(); } //连接数据库 private function db_connect(){ $this->link=mysqli_connect($this->host.':'.$this->port,$this->user,$this->pass); if(!$this->link){ echo "数据库连接失败<br>"; echo "错误编码".mysqli_errno($this->link)."<br>"; echo "错误信息".mysqli_error($this->link)."<br>"; exit; } } //设置字符集 private function db_charset(){ mysqli_query($this->link,"set names {$this->charset}"); } //选择数据库 private function db_usedb(){ mysqli_query($this->link,"use {$this->db}"); } //私有的克隆 private function __clone(){ die('clone is not allowed'); } //公用的静态方法 public static function getIntance(){ if(self::$dbcon==false){ self::$dbcon=new self; } return self::$dbcon; } //执行sql语句的方法 public function query($sql){ $res=mysqli_query($this->link,$sql); if(!$res){ echo "sql语句执行失败<br>"; echo "错误编码是".mysqli_errno($this->link)."<br>"; echo "错误信息是".mysqli_error($this->link)."<br>"; } return $res; } //获得最后一条记录id public function getInsertid(){ return mysqli_insert_id($this->link); } /** * 查询某个字段 * @param * @return string or int */ public function getOne($sql){ $query=$this->query($sql); return mysqli_free_result($query); } //获取一行记录,return array 一维数组 public function getRow($sql,$type="assoc"){ $query=$this->query($sql); if(!in_array($type,array("assoc",'array',"row"))){ die("mysqli_query error"); } $funcname="mysqli_fetch_".$type; return $funcname($query); } //获取一条记录,前置条件通过资源获取一条记录 public function getFormSource($query,$type="assoc"){ if(!in_array($type,array("assoc","array","row"))) { die("mysqli_query error"); } $funcname="mysqli_fetch_".$type; return $funcname($query); } //获取多条数据，二维数组 public function getAll($sql){ $query=$this->query($sql); $list=array(); while ($r=$this->getFormSource($query)) { $list[]=$r; } return $list; } public function selectAll($table,$where,$fields='*',$order='',$skip=0,$limit=1000) { if(is_array($where)){ foreach ($where as $key => $val) { if (is_numeric($val)) { $condition = $key.'='.$val; }else{ $condition = $key.'=\"'.$val.'\"'; } } } else { $condition = $where; } if (!empty($order)) { $order = " order by ".$order; } $sql = "select $fields from $table where $condition $order limit $skip,$limit"; $query = $this->query($sql); $list = array(); while ($r= $this->getFormSource($query)) { $list[] = $r; } return $list; } /** * 定义添加数据的方法 * @param string $table 表名 * @param string orarray $data [数据] * @return int 最新添加的id */ public function insert($table,$data){ //遍历数组，得到每一个字段和字段的值 $key_str=''; $v_str=''; foreach($data as $key=>$v){ // if(empty($v)){ // die("error"); // } //$key的值是每一个字段s一个字段所对应的值 $key_str.=$key.','; $v_str.="'$v',"; } $key_str=trim($key_str,','); $v_str=trim($v_str,','); //判断数据是否为空 $sql="insert into $table ($key_str) values ($v_str)"; $this->query($sql); //返回上一次增加操做产生ID值 return $this->getInsertid(); } /* * 删除一条数据方法 * @param1 $table, $where=array('id'=>'1') 表名 条件 * @return 受影响的行数 */ public function deleteOne($table, $where){ if(is_array($where)){ foreach ($where as $key => $val) { $condition = $key.'='.$val; } } else { $condition = $where; } $sql = "delete from $table where $condition"; $this->query($sql); //返回受影响的行数 return mysqli_affected_rows($this->link); } /* * 删除多条数据方法 * @param1 $table, $where 表名 条件 * @return 受影响的行数 */ public function deleteAll($table, $where){ if(is_array($where)){ foreach ($where as $key => $val) { if(is_array($val)){ $condition = $key.' in ('.implode(',', $val) .')'; } else { $condition = $key. '=' .$val; } } } else { $condition = $where; } $sql = "delete from $table where $condition"; $this->query($sql); //返回受影响的行数 return mysqli_affected_rows($this->link); } /** * [修改操作description] * @param [type] $table [表名] * @param [type] $data [数据] * @param [type] $where [条件] * @return [type] */ public function update($table,$data,$where,$limit=0){ //遍历数组，得到每一个字段和字段的值 $str=''; foreach($data as $key=>$v){ $str.="$key='$v',"; } $str=rtrim($str,','); if(is_array($where)){ foreach ($where as $key => $val) { if(is_array($val)){ $condition = $key.' in ('.implode(',', $val) .')'; } else { $condition = $key. '=' .$val; } } } else { $condition = $where; } if (!empty($limit)) { $limit = " limit ".$limit; }else{ $limit=''; } //修改SQL语句 $sql="update $table set $str where $condition $limit"; $this->query($sql); //返回受影响的行数 return mysqli_affected_rows($this->link); } } ?>
使用方法
- 对DB类中__construct()中的配置信息，进行符合自己数据库的修改
- include 引入DB类
- 使用DB类中的方法需要先进行实例化，以插入数据为例：
$db = DB::getIntance(); $insert_data = ['order_id'=>'10010','order_amount' = '200.00','status'=> 1]; $res = $db->insert('order_info',$insert_data);
