<?php
/**
 * mysql db class
 * insert($table,$data) 表名，array 插入字段和值
 * delete($table,$condition)
 * update($table,$data,$condition)表名，array更新字段和值,更新条件
 */





class DB{
    private $conn;
    private $host = '127.0.0.1';
    private $user = 'root';
    private $psd = 'myoa888';
    public $dbname = 'TD_OA';
            
    function __construct() {
        $this->conn = mysqli_connect($this->host, $this->user, $this->psd, $this->dbname, '3336');
    }
    
    
    /**
     * 执行一个sql语句,返回mysql资源
     * @param type string $sql
     * @return type mysql result
     */
    function query($sql){
        zlog($sql);
        return mysqli_query($this->conn, $sql);
    }
    
    /**
     * 转换传入的数组 为 sql insert
     * @param type array $data
     * @return type
     */
    private function filter_data($data){
        $keys = array_keys($data);
        $values = array_values($data);
        foreach($keys as &$key){
            $key="`$key`";
        }
        foreach($values as &$value){
            if(is_string($value)){
                $value = "'$value'";
            }else if(is_array($value)){
                if(is_string($value[1])){
                    $value[1] = "'{$value[1]}'";
                }
            }
        }
        return [$keys,$values];
    }
    
     /**
     * 返回上一次 插入数据库的id号
     * @return type
     */
    private function insert_id() {
        $id = mysqli_insert_id($this->conn);
        return $id;
    }
    
    /**
     * 传入一个表单名称和数组，将其插入数据库 返回插入后的索引id
     * @param type $table 
     * @param type $data 关联数组
     * @return int id
     */
    function insert($table,$data){
        list($keys,$values) = $this->filter_data($data);
        $sql = "INSERT INTO $table(";
        $sql .= implode(",",$keys);
        $sql .= ") VALUES(";
        $sql .= implode(",",$values);
        $sql .= ")";  
        $this->query($sql);
        return $this->insert_id();
    }
    
    /**
     * 返回上一次 query 影响的行数
     */
    private function affected_num(){
        $num = mysqli_affected_rows($this->conn);
        return $num;
    }

    /**
     * 传入一个表名 数组 条件更新一个数据
     * @param type $table
     * @param type $data
     * @param type $condition 更新条件
     * @return boolean or int num
     */
    function update($table,$data,$condition){
        list($keys,$values) = $this->filter_data($data);
        $sql = "UPDATE  `$table` set ";
        $count = count($keys);
        for($i=0;$i<$count;$i++){
            if($i + 1 == $count){
                $sql .= " {$keys[$i]} = {$values[$i]}";
            }else{
                $sql .= " {$keys[$i]} = {$values[$i]},";
            }
        }
        $sql .= " where $condition";
        echo $sql;
        $res = $this->query($sql);
        if($this->error()){
            return false;
        }else{
            return $this->affected_num();
        }
    }
   
    
   /**
    * 传入一个表名,条件 删除一条数据
    * @param type $table
    * @param type $condition
    * @return boolean
    */
    function  delete($table,$condition){
        $sql = "DELETE FROM `$table` WHERE $condition";
        //echo $sql;
        $res = $this->query($sql);
        if($this->error()){
            return false;
        }else{
            return $this->affected_num();
        }
    }
    
    /**
     * select 返回 数组
     * @param type $table
     * @param type $filter
     * @param type $condition
     * @return boolean
     */
    function select($table,$filter="*",$condition="1"){
        $sql = "select $filter from $table where $condition";
        //echo $sql;
        $res = $this->query($sql);
        if($this->error()){
            return FALSE;
        }
        $rows = [];
        if(mysqli_num_rows($res) == 1){
            $row = mysqli_fetch_assoc($res);
            return $row;
        }elseif (mysqli_num_rows($res) > 1) {
           while ($row = mysqli_fetch_assoc($res)){
               $rows[] = $row;
           } 
           return $rows;
        }else{
            return false;
        }
    }
    
    
    function error(){
        return mysqli_errno($this->conn);
    }
    
    public function close(){  
        mysqli_close($this->conn);
    }


    
}
?>