Question

public function getComparisonStudentsByMonth()
{   
    $last_month = date('m', strtotime('-2 month'));
    $previus_month = date('m', strtotime('-1 month'));

    return
    $this->db->select('MONTH('student_add_date')', date('m'));
    $this->db->where('student_add_date <= DATE_ADD(NOW(),INTERVAL 30 DAYS)');
    $query = $this->db->get('students')->result();
}

问题

用户每月插入新学生和管理页面应显示月份之间的百分比比较。我应该像上个月那样100％与当月比较。我理解逻辑但是如何处理MySql。

Answer 1

要获得每个月的所有百分比，您可以使用它：

out = 10

两个月之间需要在查询中指定月份。例如，我将在9月（9）和oktober（10）

搜索

SELECT (MONTH(student_add_date)) AS month_temp, ((count(*) /(SELECT count(*) FROM students)) * 100)percentage from students group by month_temp

在codeigniter中，您可以像这样运行自定义查询：

SELECT 
(MONTH(student_add_date)) AS month_temp, 
((count(*) /(SELECT count(*) FROM students WHERE MONTH(student_add_date) = 9 OR MONTH(student_add_date) = 10)) * 100)percentace 
from students 
WHERE 
MONTH(student_add_date) = 9 
OR 
MONTH(student_add_date) = 10 
group by month_temp

Answer 2

  public class AlarmReceiver extends BroadcastReceiver {
GPSTracker gps;
double newLat, newLong;
String aString;
String bString;

@Override
public void onReceive(Context context, Intent intent) {

    updateYourActivity(context);
}

private void updateYourActivity(Context context) {

    Intent intent = new Intent("some_unique_name");

    // put whatever data you want to send, if any
    // intent.putExtra("message", message);

    gps = new GPSTracker(context);

    // check if GPS enabled
    if(gps.canGetLocation()){

        newLat = gps.getLatitude();
        newLong = gps.getLongitude();

        aString = Double.toString(newLat);
        bString = Double.toString(newLong);
        // lat1.setText(""+latitude);
        //long1.setText(""+longitude);

    Log.e("new lat",""+aString);
        Log.e("new long",""+bString);
    }else{

        gps.showSettingsAlert();
    }

    intent.putExtra("lat", aString);
    intent.putExtra("long", bString);
    context.sendBroadcast(intent);

}

 }

我应该按月比较学生

问题

2 个答案: