从现有的SQLite数据库Android查询数据

Question

I followed this tutorial: http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/ Created db with SQLite Database Browser, put db file in "assets" folder etc..

Here my db structure created using SQLite Database Browser with instructions in tutorial link;

Then i added this method to end of DataBaseHelper class;

public ArrayList<market> getMarkets() {

    String table = "markets";
    ArrayList<market> markets = new ArrayList<market>();
    market mrkt = new market();

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery("SELECT * FROM " + table, null);

    if(cursor.moveToFirst()) {
        cursor.moveToNext();
        do {
            mrkt.market_id = cursor.getInt(cursor.getColumnIndex("marketid"));
            mrkt.market_name = cursor.getString(cursor.getColumnIndex("name"));
            mrkt.market_telno = cursor.getInt(cursor.getColumnIndex("telno"));
            mrkt.market_location = cursor.getString(cursor.getColumnIndex("location"));
            mrkt.market_hours = cursor.getString(cursor.getColumnIndex("hours"));
            markets.add(mrkt);
        }while(cursor.moveToNext());
    }

    cursor.close();
    db.close();
    return markets;
}

and i try to show first market's informations on textview with these lines in activity class:

     myDbHelper = new DataBaseHelper(this);
     markets = new ArrayList<market>();

     myDbHelper.createDataBase();
     myDbHelper.openDataBase();
     markets = myDbHelper.getMarkets();

     id.setText(markets.get(0).getMarket_id());
     name.setText(markets.get(0).getMarket_name());
     telno.setText(markets.get(0).getMarket_telno());
     loc.setText(markets.get(0).getMarket_location());
     hours.setText(markets.get(0).getMarket_hours());

However i got logcat error:

04-12 23:40:24.477: E/SQLiteLog(30698): (1) no such table: markets

i checked data/data file and there is not my db file i followed tutorial line by line but i dont know why i can not create table or sqlite database properly ? i tried .db, .sqlite3 extensions.. if i'm wrong then what should be my db file extension ? please help..

(note: i have cyanogenmod 11.0 on my phone)

Answer 1

I am not sure what is the problem but this code:

if(cursor.moveToFirst()) {
    cursor.moveToNext();
    do {
        mrkt.market_id = cursor.getInt(cursor.getColumnIndex("marketid"));
        mrkt.market_name = cursor.getString(cursor.getColumnIndex("name"));
        mrkt.market_telno = cursor.getInt(cursor.getColumnIndex("telno"));
        mrkt.market_location = cursor.getString(cursor.getColumnIndex("location"));
        mrkt.market_hours = cursor.getString(cursor.getColumnIndex("hours"));
        markets.add(mrkt);
    }while(cursor.moveToNext());
}

skips the first row of the query. With cursor.moveToFirst() you are already pointing to the first row in the table, but you do additional cursor.moveToNext() which skips the first row, and goes to the second.

Answer 2

You didn't define a table. I'm assuming as it wasn't in the tutorial. This is the line and it should be after the DATABASE_NAME and DATABASE_VERSION, and before the lines to identify the columns:

public static final String TABLE_NAME = "markets";

If you fixed it with other code, please let me know! I've been working on somet