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封装增删改查

• April 20, 2019 • Read: 792 • Web Program

封装连接数据库函数

链接数据库   charset 默认为utf8  可选参数
      function conn($host,$user,$password,$database,$charset="utf8"){
          $link = mysqli_connect($host, $user, $password, $database);
            mysqli_set_charset($link, $charset);
        return $link;
      }
调用方法
        $link = conn("127.0.0.1", "root", "root", "k8911");

封装查询函数

查询数据库 $link:查询函数返回的结果  $cols:默认为* 可以为字段名 $group:分组 $order:排序 $limit:分页  function select($link,$tbName,$cols="*",$where="",$group="",$order="",$limit=""){
      // 传递 条件
      if($where != ""){
        $where = " where ".$where;
      }
        if($group != ""){
        $group = " group by ".$group;
      }
          if($order != ""){
        $order = " order by ".$order;
      }
          if($limit != ""){
        $limit = " limit ".$limit;
      }
      // 组装select 语句
     $sql = "select $cols from $tbName $where $group $order $limit";
     //echo $sql;
      $result =  mysqli_query($link, $sql);
      if($result === flase){
          exit("查询语句有误!!!");
      }else{
           $arr = mysqli_fetch_all($result,MYSQLI_ASSOC);
      }
         mysqli_free_result($result);
         return $arr;  // 返回数据
  }
调用方法
$arr= select($link, "stus","*",null,null,null,"0,10");//查询stus这个表里面的从0开始的10条数据

封装删除数据函数

封装删除数据函数  
function del($link,$tbName,$where){
      //组装sql语句 
      if($where == null){
          $sql = "truncate $tbName";
      }else{
              $sql = "delete from $tbName  where $where";
      }
    //echo $sql;
      mysqli_query($link, $sql);
      return  mysqli_affected_rows($link);
  }
调用方法
$del = ($link,stus,"");//清空stus里面所有数据 (truncate stus)
$del = ($link,stus,"id=1");//删除stus表里面id为1的数据

封装增加函数

  function add($link,$tbname,$arr){
     $keys = array_keys($arr);  // [name,sex,cid]
     $cols = join(",", $keys);
     $vals = array_values($arr);  // [memeda,男] 
     $values = "'".join("','", $vals)."'";
       $sql = "insert $tbname($cols) value ($values)";
     //echo $sql;
     mysqli_query($link, $sql);
     return mysqli_affected_rows($link);
  }
调用方法
      $res = add($link,"stus",$_POST);//post传过来的数组

封装修改函数

function save($link,$tbname,$arr,$where){
           $str ="";
          foreach($arr as $k=>$v){
            $str .= $k."='".$v."',";
          }
         $str =  trim($str,",");
        if($where !=null){
            $where = " where ".$where;
        }
       $sql = "update $tbname set $str $where";
      mysqli_query($link, $sql);
      return  mysqli_affected_rows($link); 
  }
    调用方法
        save($link,"stus",$_POST,"sid=$sid");
    

复杂语句处理封装

function query($link,$sql){
        
        $arr = ["select","update","delete","insert"];
        // 过滤空格
          $sql= trim($sql);  // trim(str,",")
          $type= substr($sql, 0,6);
          if(in_array($type, $arr)){
                if($type == "select"){
                    // 查询
                    // @  错误抑制符
                    @ $result = mysqli_query($link, $sql);  // false  obj
                    if($result === false){
                        exit("查询语句拼写有误!!!");
                    }else{
                     @ $arr =    mysqli_fetch_all($result,MYSQLI_ASSOC);
                    return $arr;
                    }
                }else{
                    // 增删改
                    $re= mysqli_query($link, $sql); // true false
                    if($re === false){
                        exit("语句拼写有误!!");
                    }else{
                         return mysqli_affected_rows($link);
                    }
                }
          }else{
              
             exit("sql语句非法!!!");
          }
    }
调用方法
query($link,"select tabname * from xxx");

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Last Modified: April 21, 2019
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