如何按日期以字符串形式订购房间结果 [英] How to Order Room results by Date as String

问题描述

我有一个room database.我有date列，并且已另存为string.

I have a room database. I have a column for date and it's saved as string.

我使用此query来对我的列进行排序:

I used this query for sort my column :

@Query("SELECT * FROM session WHERE class_id = :classId ORDER BY session_date ASC")
List<SessionEntry> getAllSessions(int classId);

结果:

    1398/11/25
    1398/11/29
    1398/12/5
    1398/2/14
    1398/4/25
    1398/6/17
    1398/6/30
    1398/7/9
    1398/9/14

但是我想这样排序:

    1398/2/14
    1398/4/25
    1398/6/17
    1398/6/30
    1398/7/9
    1398/9/14
    1398/11/25
    1398/11/29 
    1398/12/5

有什么方法可以按日期作为字符串排序而不修改数据库结构吗?

Is there any way I could order by Date as String without modifying the database structure ?

推荐答案

我找到了解决方法，但这不是最好的方法.

I found a solution but it's not best.

这种方法适用于无法将Date Column从字符串更改为另一种类型的情况

This way is for when you can't change your Date Column from String to another type

List<SessionEntry> sessionEntries = mDb.sessionDao().getAllSessions(classId);
Collections.sort(sessionEntries, comparing(SessionEntry::convertStringToDate));

会话条目:

public class SessionEntry {
    .
    .
    .
    public Date convertStringToDate() {
        try {
            return new SimpleDateFormat("yyyy/MM/dd").parse(getSessionDate());
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
}

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