我有一个sqlite数据库，其中包含一列任务，其中包含一列dueDates。我想过滤掉大于明天日期的日期。因此，如果明天的日期是4月29日，我应该比明天晚些时候得到日期。
为此，我已将字符串转换为日期。格式为：
Calendar calendar = Calendar.getInstance();
dateToday = calendar.getTime();
SimpleDateFormat df = new SimpleDateFormat("d MMM yyyy");
dueDateToday = df.format(dateToday);
calendar.add(Calendar.DAY_OF_YEAR, 1);
dueTomorrow = calendar.getTime();
dueDateTomorrow = df.format(dueTomorrow);
，查询是：
public ArrayList<Task> getDueDatesLater(String tomorrow) {
ArrayList<Task> conList = new ArrayList<Task>();
String selectQuery = "SELECT * FROM " + TASK_TABLE + " WHERE " + KEY_DUE_DATE + " > '" + tomorrow + "'" ;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
Task task = new Task();
task.setId(Integer.parseInt(cursor.getString(0)));
task.setTitle(cursor.getString(1));
task.setTaskPriority(Integer.parseInt(cursor.getString(2)));
task.setAlertDate(cursor.getString(3));
task.setAlertTime(cursor.getString(4));
task.setDueDate(cursor.getString(5));
task.setDueTime(cursor.getString(6));
task.setList(Integer.parseInt(cursor.getString(7)));
task.setStatus(Integer.parseInt(cursor.getString(8)));
task.setAlertId(Integer.parseInt(cursor.getString(9)));
conList.add(task);
} while (cursor.moveToNext());
}
return conList;
}
但是我的列表为0.没有日期。也许我的查询错了。请帮忙。
编辑：正如所建议的那样。
public ArrayList<Task> getDueDatesLater(String tomorrow) {
ArrayList<Task> conList = new ArrayList<Task>();
String selectQuery = "SELECT * FROM " + TASK_TABLE ;
Date dueDate,tomorrowDate;
SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat();
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
try {
if (cursor.moveToFirst()) {
do {
Task task = new Task();
task.setId(Integer.parseInt(cursor.getString(0)));
task.setTitle(cursor.getString(1));
task.setTaskPriority(Integer.parseInt(cursor.getString(2)));
task.setAlertDate(cursor.getString(3));
task.setAlertTime(cursor.getString(4));
task.setDueDate(cursor.getString(5));
task.setDueTime(cursor.getString(6));
task.setList(Integer.parseInt(cursor.getString(7)));
task.setStatus(Integer.parseInt(cursor.getString(8)));
task.setAlertId(Integer.parseInt(cursor.getString(9)));
dueDate = simpleDateFormat1.parse(task.getDueDate());
tomorrowDate = simpleDateFormat1.parse(tomorrow);
if (dueDate.getTime() > tomorrowDate.getTime()) {
conList.add(task);
}
Log.d("laterQuery", selectQuery);
//conList.add(task);
} while (cursor.moveToNext());
}
}
catch (ParseException e) {
}
return conList;
}
仍然列表返回0.
同样我想知道有多少任务的日期晚于明天。
public int getPendingTasksLaterDays(String tomorrow) {
ArrayList<Task> conList = new ArrayList<Task>();
String selectQuery = "SELECT * FROM " + TASK_TABLE + " WHERE " + KEY_TASK_STATUS + " = 0";
Date dueDate,tomorrowDate;
SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("d MMM yyyy", Locale.ENGLISH);
SQLiteDatabase db = this.getWritableDatabase();
Cursor mCount= db.rawQuery(selectQuery,null);
if (mCount.moveToFirst()) {
do {
count = mCount.getInt(0);
} while (mCount.moveToNext());
}
Log.d("query",selectQuery);
Log.d("count",String.valueOf(count));
mCount.close();
return count;
}
如何添加？
答案 0 :(得分：0)
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String to_date = sdf.format(new Date());
crs = db.rawQuery(
"SELECT _id, date_from, date_to, done_or_not, list_name " +
"FROM list_tbl " +
"WHERE " +
"date_from <= Datetime('"+to_date+"') AND date_to >= Datetime('"+to_date+"')", null);
答案 1 :(得分：0)
只需将过滤器放入查询结果中即可。
public ArrayList<Task> getDueDatesLater(String tomorrow) {
ArrayList<Task> conList = new ArrayList<Task>();
String selectQuery = "SELECT * FROM " + TASK_TABLE ;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
try {
if (cursor.moveToFirst()) {
do {
Task task = new Task();
task.setId(Integer.parseInt(cursor.getString(0)));
task.setTitle(cursor.getString(1));
task.setTaskPriority(Integer.parseInt(cursor.getString(2)));
task.setAlertDate(cursor.getString(3));
task.setAlertTime(cursor.getString(4));
task.setDueDate(cursor.getString(5));
task.setDueTime(cursor.getString(6));
task.setList(Integer.parseInt(cursor.getString(7)));
task.setStatus(Integer.parseInt(cursor.getString(8)));
task.setAlertId(Integer.parseInt(cursor.getString(9)));
dueDate = simpleDateFormat1.parse(task.getDueDate());
tomorrowDate = simpleDateFormat1.parse(tomorrow);
if (dueDate.getTime() > tomorrowDate.getTime()) {
conList.add(task);
}
} while (cursor.moveToNext());
}
}
catch (ParseException e) {
}
return conList;
}
答案 2 :(得分：0)
如果您想比较数据库中的任何两个日期或在数据库上应用查询，您的日期格式可以采用以下任何格式：
YYYY-MM-DD
YYYY-MM-DD HH:MM
YYYY-MM-DD HH:MM:SS
YYYY-MM-DD HH:MM:SS.SSS
YYYY-MM-DDTHH:MM
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SS.SSS
HH:MM
HH:MM:SS
HH:MM:SS.SSS
//您的查询
String selectQuery = "SELECT * FROM " + TASK_TABLE + " WHERE " + KEY_DUE_DATE + " > '" +2016-04-30 + "'" ;
或示例
SELECT * FROM test WHERE date BETWEEN "2011-01-11" AND "2011-8-11"
//下面的方法更改您的日期格式，如果您想在UI上以不同的格式显示日期
//
/**
* Change date for mate to original to target date format
* return formatted date string
* @param myDate
* @return String
*/
public static String changeDateFormatIntoYYYYMMDDHHMMSS(String myDate,
String originalDateFormat,
String targetDateFormat){
String formattedDate="";
try {
DateFormat originalFormat = new SimpleDateFormat(originalDateFormat);//AppConstant.DATE_FORMAT_FOR_UI);
DateFormat targetFormat = new SimpleDateFormat(targetDateFormat);//AppConstant.DATE_FORMAT_FOR_DB);
Date date = originalFormat.parse(myDate);
formattedDate = targetFormat.format(date);
} catch (ParseException e) {
e.printStackTrace();
}
return formattedDate;
}
// calling Example
String changeDate= changeDateFormatIntoYYYYMMDDHHMMSS("2016/04/30", DATE_FORMAT_FOR_DB,DATE_FORMAT_FOR_UI);
// String Formate
String DATE_FORMAT_FOR_DB="yyyy/MM/dd HH:mm:ss";
String DATE_FORMAT_FOR_UI="MMM dd, yyyy hh:mm a";
本“准则”有助于您实现自己的功能