Comment classer ma base de données SQLITE par ordre décroissant, pour une application Android ?

Question

Quelle est la méthode la plus efficace pour afficher mes données par ordre décroissant ?

public String getRank() {

    String[] rank = new String[]{ KEY_ROWID };
    Cursor c = scoreDb.query(DATABASE_TABLE, rank, null, null, null, null, null);   //reading information from db.
    String rankResult = "";

    int iRow = c.getColumnIndex(KEY_ROWID); //Cursor looking for column setting equal to these ints.

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { 
        //Move to first row - where cursor starts and moves to next row as long it is not after last row.
        rankResult = rankResult + c.getString(iRow) + "\n"; 
        //Returning value of row that it is currently on.
    }
    return rankResult;  //returning result
}

public String getName() {

    String[] name = new String[]{ KEY_NAME };
    Cursor c = scoreDb.query(DATABASE_TABLE, name, null, null, null, null, null);   //reading information from db.
    String nameResult = "";

    int iRow1 = c.getColumnIndex(KEY_NAME); //Cursor looking for column setting equal to these ints.

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { 
        //Move to first row - where cursor starts and moves to next row as long it is not after last row.
        nameResult = nameResult + c.getString(iRow1) + "\n"; 
        //Returning value of row that it is currently on.
    }
    return nameResult;  //returning result
}

public String getScore() {

    String[] score = new String[]{ KEY_SCORE };
    Cursor c = scoreDb.query(DATABASE_TABLE, score, null, null, null,null, null);   //reading information from db.
    String scoreResult = "";

    int iRow2 = c.getColumnIndex(KEY_SCORE); //Cursor looking for column setting equal to these ints.

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { 
        //Move to first row - where cursor starts and moves to next row as long it is not after last row.
        scoreResult = scoreResult + c.getString(iRow2) + "\n"; 
        //Returning value of row that it is currently on.
    }
    return scoreResult; //returning result
}

Answer 1

C'est une chose terrible ! Ça me coûte quelques heures ! C'est ma table des lignes :

private String USER_ID = "user_id";
private String REMEMBER_UN = "remember_un";
private String REMEMBER_PWD = "remember_pwd";
private String HEAD_URL = "head_url";
private String USER_NAME = "user_name";
private String USER_PPU = "user_ppu";
private String CURRENT_TIME = "current_time";

Cursor c = db.rawQuery("SELECT * FROM " + TABLE +" ORDER BY " + CURRENT_TIME + " DESC",null);

Chaque fois que je mets à jour la table, je mets à jour le CURRENT_TIME pour le tri. Mais je trouve que cela ne fonctionne pas, le résultat n'est pas trié comme je le souhaite. Finalement, j'ai découvert que la colonne "current_time" est la ligne par défaut de sqlite.

La solution est de renommer la colonne "cur_time" au lieu de "current_time".