Question

我试图在from和to日期之间获取数据。我在sql lite上做过，它有效我尝试在android编码部分，它不起作用，你们可以请帮助

protected void adddata1() throws ParseException {

Database db=new Database(Reportmonth.this);
SQLiteDatabase sb=db.getReadableDatabase();


String a=from.getText().toString();
String b=to.getText().toString();

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");


 Date a1=sdf.parse(a);//convert string to date
Date b1=sdf.parse(b);//convert string to date


Cursor cus=sb.rawQuery("select * from expenz where daty between '" + a1 +"' AND '"+b1+"'",null);

cus.moveToFirst();
 for(int i=0;i<cus.getCount();i++)
     {


     if(cus!=null) //i think the error starts from this onwards.        
     {                           
         soi.setText(cus.getString(0));


         Log.i("",cus.getString(0));

          desc.setText(cus.getString(3));

          dat.setText(cus.getString(1));

          woc.setText(cus.getString(2));


          amount.setText(cus.getString(5));

          adddata();

          search.setClickable(false);

  }      
     cus.moveToNext();

     } 

    }

Answer 1

不建议将date作为varchar存储在数据库中，就像处理像你这样的情况一样，这是一个真正的痛苦

还在下面我展示了一个解决方法，您可以从表中提取所有数据，将表格中的日期列从string转换为Date对象，然后进行比较。但是，当数据库中的行非常高时，这将会非常强烈地达到性能。

//For storing the rows that are in between the date range
ArrayList<HashMap<String, String>> rowList = new ArrayList<HashMap<String, String>>();

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

//Important that the date should be in the same format as specified above
Date startDate = sdf.parse(a);//convert string to date
Date endDate = sdf.parse(b);//convert string to date

Cursor cus = sb.rawQuery("select * from expenz",null);

if (cursor.moveToFirst()) {
    do {
        try {
            //Converting the database `varchar date` to `Date` object here
            //Here cursor.getString(X) should be the column number of your daty column
            //And also the date format in the database should also be same as "yyyy-MM-dd"
            Date thisDate = sdf.parse(cursor.getString(X));

            // Check if the database date is within the range
            if (thisDate.after(startDate) && thisDate.before(endDate)) {
                HashMap<String, String> map = new HashMap<String, String>();

                //Here have the number of columns you want to have according to your database
                map.put("column0", cursor.getString(0));
                map.put("column1", cursor.getString(1));
                map.put("column2", cursor.getString(2));
                map.put("column3", cursor.getString(3));
                map.put("column4", cursor.getString(4));
                map.put("column5", cursor.getString(5));

                rowList.add(map);
            }
        } catch (ParseException e) {
            e.printStackTrace();
        }
    } while (cursor.moveToNext());
}

// Now here the rowList will have the rows between the specified date range

您可以修改最内部if loop以满足您的要求。

我希望它有所帮助！

如何在android（而不是sqlite）中的两个日期之间获取数据？

1 个答案: