PHP开发中MySQL的操作类详解

db=new mysqli($host,$user,$pwd,$name); //数据库连接

 

    if(mysqli_connect_errno()){

      echo "数据库连接错误".mysqli_connect_errno();

      exit();

    }

    $this->db->query("set names utf8");

    $this->table=$table_names;

    $this->opt['field']="*";

    $this->opt['where']=$this->opt['Order']=$this->opt['Limit']=$this->opt['Group']='';

//    var_dump($this->opt['where']);

    //$this->M($table_names);

 

  }

 

  //数据库连接

//  protected function M($table_name){

//    $this->db=new mysqli(DBHOST,DBUSER,DBPWD,DBNAME);

//

//    if(mysqli_connect_errno()){

//      echo "数据库连接错误".mysqli_connect_errno();

//      exit();

//    }

//    $this->db->query("set names utf8");

//    $this->table=$table_name;

//  }

 

  //表中的字段

 

  public function tbField(){

    $desc=$this->db->query("DESC {$this->table}");

    $fieldArr=array();

    while(($row=$desc->fetch_assoc())!=false){

      $fieldArr[]=$row['Field'];

    }

    // var_dump($fieldArr);

    return $fieldArr;

  }

 

  //查询字段

  public function field($filed){

    //拆分字段

    $filedArr=is_string($filed)?explode(",",$filed):$filed;

    if(is_array($filedArr)){

      $filed='';

      foreach($filedArr as $v){

        $filed.="'".$v."'".",";

      }

    }

    //var_dump($filed);

    return rtrim($filed,",");

 

  }

 

  //判断字段是否存在

  public function isfield($fileds)

  {

    $filedArr=is_string($fileds)?explode(",",$fileds):$fileds;

    $tbFiled=$this->tbField();

    //var_dump( $tbFiled);

    foreach($filedArr as $v){

      if(!in_array($v,$tbFiled)){

         echo "字段输入发错";

      }

    }

 

  }

  //条件语句

  public function where($where){

     $this->opt['where']=is_string($where)?" WHERE {$where}":"不是字符串";

    return $this;

 

 

 

  }

  //Limit

  public function Limit($limit){

     $this->opt['Limit']=is_string($limit)?" Limit {$limit}":"不是字符串";

    return $this;

 

 

  }

  public function Order($order){

     $this->opt['Order']=is_string($order)?" Order By {$order}":"不是字符串";

    return $this;

 

 

  }

  public function Group($group){

    $this->opt['Group']=is_string($group)?" Group BY {$group}":"不是字符串";

    return $this;

 

 

  }

 

  // 查询字符串

  public function select(){

    $sql="select * from {$this->table} {$this->opt['where']} {$this->opt['Group']} {$this->opt['Limit']} {$this->opt['Order']}";

    return $this->fetch($sql);

  }

  //结果集查询

  public function fetch($sql){

    $result=$this->db->query($sql);

    $sqlarr=array();

    while(($row=$result->fetch_assoc())!=false){

      $sqlarr[]=$row;

    }

    // var_dump($sqlarr);

    return $sqlarr;

  }

  //无结果集查询

  public function querys($sql){

    $sqls=$this->db->query($sql);

    return $this->db->affected_rows;

  }

 

  //删除语句

  public function delete($where=array()){

    if($where=="" && empety($this->opt['where'])) die(" 不能为空");

    if($where!=""){

      if(is_array($where)){

        $where=implode(",",$where);

      }

      $this->opt['where']=" WHERE id IN({$where})";

    }

    $sql="delete from {$this->table} {$this->opt['where']} {$this->opt['Limit']}";

    var_dump($sql);

    //return $this->query($sql);

  }

  //数组键名

  public function key($key){

    if(!is_array($key))die("非法数组");

    $keys="";

    foreach($key as $v){

      $keys.=$v.",";

 

    }

    return rtrim($keys,",");

  }

  //数组值

  public function value($value){

    if(!is_array($value))die("非法数组");

    $strvalue="";

    foreach($value as $v){

      $strvalue.="'".$v."'".",";

    }

    return rtrim($strvalue,",");

  }

 

  //添加语句

  public function add($filed){

    if(!is_array($filed)) die("非法数组");

    $fileds=$this->key(array_keys($filed)); //返回数组中的键名

    //var_dump($fileds);

    $values=$this->value(array_values($filed));

    $sql="insert into {$this->table}({$fileds})VALUES($values)";

    //var_dump($sql);

    return $this->querys($sql);

  }

 

  //查找单条记录

  public function find($field,$id){

    $sql="select {$this->opt['field']} from {$this->table} {$this->where($field.'='."'".$id."'")}";

    var_dump($sql);

    return $this->fetch($sql);

 

  }

  //更新语句

  public function save($arrs){

    if(!is_array($arrs))die("非法的数组");

    //if(empty($this->opt['where']))die("条件不能为空");

    $str="";

    while(list($k,$v)=each($arrs))

    {

      $str="{$k}="."'{$v}',";

    }

    $str=rtrim($str,",");

    $sql="Update {$this->table} set {$str}{$this->opt['where']}";

 

    return $this->querys($sql);

 

 

  }

  //获取总记录数

  public function counts(){

 

    $sql="select 'id' from {$this->table}{$this->opt['where']}";

    //var_dump($sql);

    return $this->querys($sql);

  }

 

 

}

 

$db=new Mysqls('127.0.0.1','root','','mysql','user');