ci框架 用框架自带db 添加括号，比如 like 等等左右添加括号 解决办法

         $this->load->model('station/Station_model','Station');
         // East
         // North
         $this->Station->set_where('isdel',0);
         //连表查询地区
         $this->Station->list_attributes = 'region.text as sitone,station.North,station.East,station.state,station.stabianhao,station.staname,station.siteonename,station.sitetwoname,station.sitename,station.statype,station.settime,station.staid';
         $this->Station->join('region','region.linkageid = station.sitetwoname','left');
         if ($type!='all') {
             $this->Station->set_where('station.state',$type);
         }

         $this->Station->set_where(' (  station.sitetwoname',$sitearr,'where_in');
         $this->Station->set_where('station.siteonename',$sitearr,'or_where_in');
         $this->Station->set_where('  1 = 2 ) and 1','1','or_where_in');

         $data = $this->Station->get_stewhere_all();
         echo $this->db->last_query();die;

这样生成的sql为

 SELECT
     `dz_region`.`text` AS `sitone`,
     `dz_station`.`North`,
     `dz_station`.`East`,
     `dz_station`.`state`,
     `dz_station`.`stabianhao`,
     `dz_station`.`staname`,
     `dz_station`.`siteonename`,
     `dz_station`.`sitetwoname`,
     `dz_station`.`sitename`,
     `dz_station`.`statype`,
     `dz_station`.`settime`,
     `dz_station`.`staid`
 FROM
     `dz_station`
 LEFT JOIN `dz_region` ON `dz_region`.`linkageid` = `dz_station`.`sitetwoname`
 WHERE
     `isdel` = 0
 AND (
     `dz_station`.`sitetwoname` IN (
         '',
         '',
         '',
         '',
         '',
         ''
     )
     OR `dz_station`.`siteonename` IN (
         '',
         '',
         '',
         '',
         '',
         '',
         '',
         ''
     )
     OR 1 = 2
 )
 AND 1 IN ('')

以上

如果不采用我的办法生成的sql为

SELECT
	`dz_region`.`text` AS `sitone`,
	`dz_station`.`North`,
	`dz_station`.`East`,
	`dz_station`.`state`,
	`dz_station`.`stabianhao`,
	`dz_station`.`staname`,
	`dz_station`.`siteonename`,
	`dz_station`.`sitetwoname`,
	`dz_station`.`sitename`,
	`dz_station`.`statype`,
	`dz_station`.`settime`,
	`dz_station`.`staid`
FROM
	`dz_station`
LEFT JOIN `dz_region` ON `dz_region`.`linkageid` = `dz_station`.`sitetwoname`
WHERE
 `isdel` = 0

AND `dz_station`.`sitetwoname` IN (
	'1',
	'199',
	'203',
	'205',
	'197',
	'209',
	'208'
)
OR `dz_station`.`siteonename` IN (
	'1',
	'199',
	'203',
	'205',
	'211',
	'209',
	'208'
)

　　当然这是不满足需求的，至于为什么不用原生sql，因为数组不好处理，