android-sqlite

问题 I have incorporated Database Backup and restore in my App. This all works fine except that when I restore the database, due to the use of a singleton DBHelper along with only closing the database when the App closes, the in-memory copy of the Database continues to be used after the restore. Closing the App and re-starting uses the new database. However, rather than tell the user to do this. I would like to seamlessly access the restored database. This is the code that detects and then reports

问题 Please read before make it Duplicate. I am trying to insert longitude and latitude values in SQLite table and i want it to be unique value, after some research for that i have found this and this answers very helpful, although they both are written for simple queries and i am not able to find how to fit my query with both constraints unique and ON_CONFLICTION_REPLACE query is as follow, private static final String CREATE_USER_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_LOCATIONS + "(" + UID

问题 I need to create an android app database , but I was wondering if I should create one class that inherits SQLiteOpenHelper for each table that exists in my database ? Or should I create One class : for example MyAppDatabase that inherits from SQLiteOpenHelper and create all my tables in onCreate method as well as update and delete functions ? ANy recommendations ? 回答1: You only need one database helper for all tables in a database and thus you'd use the one onCreate method for the creation of

问题 I want to do a query as follows from an Android SQLite db: select place.permit_name, local.local_distance from tblLocal local inner join tblPlaces place on place._id = local._id order by local.local_distance asc I'm trying to use query() , instead of rawQuery() . I don't know how to specify the INNER JOIN/ON. How do I do this? final String table = PlacesDataContract.PlacesDataEntry.TABLE_NAME; final String[] columns = { PlacesDataContract.PlacesDataEntry.COLUMN_NAME_PERMIT_NAME. ,

问题 I've been looking into ways to show data from my DB in a ListView while keeping track of changes in the database. Let's say I have a chat app that shows a ListView of all the chatrooms I am a member of. the query for the adapter is SELECT * FROM CHAT_ROOM ORDER BY UPTDATE_TIME , meaning I want the chatrooms with recent activity to be shown first. as I am in the ChatroomListActivity a message is received for chatroom number 3, this means it needs to become now chatroom number one and rearrange

问题 I have created one class for database and multiple classes for tables and multiple activity classess everything works fine when I use the database class instance in activity class but at the same time when I use the database class instance in table class and run the application as soon as the control goes to getwritabledatabase I am getting exception and application is exited, below is the code for all 3 classes. Database class. public class Database extends SQLiteOpenHelper{ private static

问题 I have created one class for database and multiple classes for tables and multiple activity classess everything works fine when I use the database class instance in activity class but at the same time when I use the database class instance in table class and run the application as soon as the control goes to getwritabledatabase I am getting exception and application is exited, below is the code for all 3 classes. Database class. public class Database extends SQLiteOpenHelper{ private static

问题 I have a db imported to assets, and i read from it and randomly set text to buttons and a texview, with code below: mDbHelper.open(); Cursor c = mDbHelper.getTestData(); List<Answer> labels = new ArrayList<Answer>(); labels.add(new Answer(c.getString(2), true)); labels.add(new Answer(c.getString(3), false)); labels.add(new Answer(c.getString(4), false)); labels.add(new Answer(c.getString(5), false)); Collections.shuffle(labels); question.setText(c.getString(1)); bOdgovor1.setText(labels.get(0

问题 For some reasons(mainly large apk size even with ABI splits, anyway) i need to remove Realm completely and use Sqlite without losing data. I couldn't find a way. It seems the app must continue using Realm, or users will lost their data completely. Any idea will be appreciated 回答1: I don't think I understand fully what your problem is. If you are asking if there is a tool that will automate the data migration for you, then no, there is no such a tool. Otherwise it is rather straight forward:

问题 I want to create a table for the first time (DB version = 1), and insert into it 2 rows by default. The table needs to be created automatically by ActiveAndroid, and the records should be inserted by the SQL I wrote in 1.sql file. The table looks fine, but the rows are not inserted at all (no errors thrown). The model looks like this: @Table(name = "leagues") public class League extends Model implements Serializable{ @Column(name = "name") public String name; public static List<League> getAll