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I am not able to query a pre-created database using SQLiteAssetHelper

I am not able to query a pre-created database. I created a SQLite database using SQLiteDatabaseBrowser and I populated it. The following query works in the SQLiteDatabaseBrowser:
SELECT png FROM flags64 WHERE iso3='jpn' LIMIT 1
I moved the file in the folder "../assets/databases" in the android project into the Android Studio. This is the code used to query the database from my android app:
public class myStickerDatabase extends SQLiteAssetHelper {
private static final String DATABASE_NAME = "mysticker.db";
private static final int DATABASE_VERSION = 1;
public myStickerDatabase(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public Bitmap getFlag(String iso3) {
SQLiteDatabase db = getReadableDatabase();
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
Cursor c = db.rawQuery(String.format("SELECT png FROM flags64 WHERE iso3 = '%s' LIMIT 1", iso3), null);
c.moveToFirst();
byte[] png = c.getBlob(c.getColumnIndex("png"));
ByteArrayInputStream inputStream = new ByteArrayInputStream(png);
return BitmapFactory.decodeStream(inputStream);
}
}
Debugging the code the query does not return any records.
Update
It would seem that the database is not copied to the device.
The database size is about 250kb, but the copy in the device is about 24kb. Why?

Cannot open Database file

I have an application that creates a database file at '/storage/emulated/0/databases/mydb.db' and there are files within this DB.
I have another application which tries to open this database. But I get error code 14. Could not open database when trying to oprn the table in this db.
public class DataBaseHelper extends SQLiteOpenHelper {
public SQLiteDatabase myDataBase;
public String TABLE_NAME;
// Database Information
static final String DB_NAME = "mydb.DB";
public static final String FILE_DIR = "databases";
private String DB_PATH = Environment.getExternalStorageDirectory()
+ File.separator + FILE_DIR + File.separator + DB_NAME;
public DataBaseHelper(Context context, String name) {
super(context, name, null, 1);
TABLE_NAME = name;
}
public void openDatabase() throws SQLiteException {
String DBPath = DB_PATH + "/" +TABLE_NAME;
myDataBase = SQLiteDatabase.openDatabase(DBPath,null,SQLiteDatabase.OPEN_READWRITE);
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
I get an error at myDataBase = SQLiteDatabase.openDatabase(DBPath,null,SQLiteDatabase.OPEN_READWRITE);

Another thing to note is Environment.getExternalStorageDirectory() has been deprecated in API 29:
https://developer.android.com/reference/android/os/Environment#getExternalStorageDirectory()
This method was deprecated in API level 29.
To improve user privacy, direct access to shared/external storage devices is deprecated. When an app targets Build.VERSION_CODES.Q, the path returned from this method is no longer directly accessible to apps. Apps can continue to access content stored on shared/external storage by migrating to alternatives such as Context#getExternalFilesDir(String), MediaStore, or Intent#ACTION_OPEN_DOCUMENT.

1. Permission
Your app needs file read permission. Above Android 6.0, you need to request runtime permission.
See this: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
2. Wrong path
It seems that the path
/storage/emulated/0/databases/mydb.db
is not same as path below.
Environment.getExternalStorageDirectory()
+ File.separator + FILE_DIR + File.separator + DB_NAME
So, before open database file, compare two paths to check it is same.
if (DB_PATH.compareTo("/storage/emulated/0/databases/mydb.db")){
// Do something
}
And check the to find out it really exists.
File file = new File(myPath);
if (file.exists() && !file.isDirectory()) {
// Do something
}
Details: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database trouble

android sqlite - table data cannot be updated

the table ( i.e. vaccines) structure is :
id- auto increment primary key
dose1_date - string
dose2_date - string
The DatabaseAccessor class is as follows. The initDB() and setVaccineDates methods are called from another activity. But the database is not updated. The logged message is found in the logcat however. The DatabaseHelper class is not shown here.
public class DatabaseAccessor {
public static DataBaseHelper myDbHelper = null;
public static SQLiteDatabase rdb = null;
public static SQLiteDatabase wdb = null;
public static synchronized final void initDB(Context context) throws Exception {
if (myDbHelper == null) {
myDbHelper = new DataBaseHelper(context);
myDbHelper.openDataBase();
rdb = myDbHelper.getReadableDatabase();
wdb = myDbHelper.getWritableDatabase();
}
}
public static void setVaccineDates(String birthDate) throws SQLException{
try {
String[] selections = null;
String qry = null;
qry = "select * from vaccines order by id";
Cursor cursor = wdb.rawQuery(qry, selections);
Log.d("update qry===== ", qry);
while (cursor.moveToNext()) {
int rowID = Integer.parseInt(cursor.getString(0));
ContentValues values = new ContentValues();
values.put("dose1_date","66666");
values.put("dose2_date","7777");
wdb.update("vaccines", values, "id=?", new String[] {String.valueOf(rowID)});
//wdb.close();
}
cursor.close();
} catch (Exception e) {
e.printStackTrace();
}
}// end of method setVaccineDates
}
What to do ?
Edit : If I uncomment the wdb.close() line , I see in logcat
'06-09 04:21:05.387: W/System.err(4144): java.lang.IllegalStateException: attempt to re-open an already-closed object: SQLiteDatabase: /data/data/com.cloudsoft.vaccine/databases/vaccines2.db
'

As a newbie in android it was just a mistake out of ignorance that this situation took place: after update operation I tried to find the changes in the database file (i.e. file with .db extension sitting inside assets folder in Eclipse) through sqlite browser . But what actually happens is the app running in the device (real one or emulator) has its own database which is created from the .db extension file inside assets folder and consequent database operations only affect the app's own database leaving no touch on the database inside the mentioned folder in Eclipse. And there is the way to watch the app's very own database in the running device in Eclipse's 'File Explorer' (in DDMS mode) with the help of Questoid SQlite Manager

Android sqlite rowcount is always zero?

I've used the GUI to create a DB which has 1650 records in it.
I'm trying to query this DB but it's always returning nothing. I've tried writing a simple getrowcount() method to see if I'm getting anything at all, but it always returns zero. I must be missing something obvious here, if someone can help point out what's going on.
In my main app.java:
db = new DbHandler(this);
String sIcao1 = "ROW COUNT = " + String.valueOf(db.getRowCount());
In my dbhandler.java:
package com.jammo.mywidget4;
<snip - standard includes>
public class DbHandler extends SQLiteOpenHelper {
private static SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "airports";
private static final String TABLE_AIRPORTS = "airports";
public DbHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
db = this.getWritableDatabase();
}
#Override
public void onCreate(SQLiteDatabase db) {
db = this.getWritableDatabase();
}
int getRowCount() {
int nCount = -1;
//SQLiteDatabase db = this.getReadableDatabase();
Cursor cur = db.rawQuery("SELECT * FROM airports", null);
nCount = cur.getCount();
if (cur != null) {
//cur.moveToFirst();
//nCount = cur.getInt(0);
//if (cur.getInt (0) == 0) {
//}
}
return nCount;
}
}
In the GUI (SQLite DB Browser) I'm doing a simple
select * from airports
... and I'm getting back the full number of rows. When I debug the Java, cursor returns nothing.
Also, the DB created by the GUI is located in myapp/assets/airports.db.
Any ideas?

I think you need to include the .db in the DATABASE_NAME.
Try changing this:
private static final String DATABASE_NAME = "airports";
to this:
private static final String DATABASE_NAME = "airports.db";
Edit:
Actually I think even with this change it is not going to work for you. SQLiteOpenHelper is expecting your db file to be inside of /data/data/your.package/databases/ So I think you'll need to copy it from assets to there if you want it to work with an unmodified SQLiteOpenHelper.
See here to learn how to copy it over: Android: Accessing assets folder sqlite database file with .sqlite extension

Android SQLite Database Connection not succesfull

i encountered a little problem with my current project. I am doing an android application which needs to connect to a SQLite database to work through some statements. I believe the statements etc are fine, my only problem is the fact that the connection to the database is not succesfull.
LogCat Error:
04-18 08:20:30.688: E/Database(304): sqlite3_open_v2("jdbc:sqlite:res/raw/randomdb.db", &handle, 1, NULL) failed
So my code so far for connecting to the database is like this:
String url = "jdbc:sqlite:res/raw/randomdb.db";
SQLiteDatabase db;
db = SQLiteDatabase.openDatabase(url, null, SQLiteDatabase.OPEN_READONLY);
As you can see, i am trying to acces a database which is located in my project/res/raw folder. Does anyone see the mistake?
!!!UPDATE!!!
*I tried to go the way with SQLiteOpenHelper, but still encouner an error i cannot seem to solver. Here is my new code:*
public class DatabaseAdapter extends SQLiteOpenHelper {
private static String dbPath= "data/data/com.YourPackageName/applicationDb/";
private static String dbName = "YourDBName";
private SQLiteDatabase applicationDatabase;
private final Context applicationContext;
private boolean checkDataBase(){
File dbFile = new File( dbPath + dbName);
return dbFile.exists();
}
public void openDataBase() throws SQLException{
String fullDbPath= dbPath + dbName;
applicationDatabase = SQLiteDatabase.openDatabase( fullDbPath,null,SQLiteDatabase.OPEN_READONLY);
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
I get this error:
Implicit super constructor SQLiteOpenHelper() is undefined for default constructor. Must define an explicit constructor
Any ideas? Would be great!

if you want to connect your android application with SQLite database then you need to extends SQLiteOpenHelper
public class AbcClass extends SQLiteOpenHelper
after that you need to Override these method:
onCreate and onUpgrade
and constructor of AbcClass looks like:
public AbcClass(Context context) {
super(context, DB_NAME, null, VERSION); //public static final String DB_NAME = "test.sqlite";
}

public boolean databaseExist()
{
File dbFile = new File(DB_PATH + DB_NAME);
return dbFile.exists();
}
This is the solution...
OR-----------------------
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}

I think the path you specify is not the correct one and so as mentioned in one of the other answers the database is not found. However I had never used the method openDatabase to read from the raw folder so I do not know which is the correct path.
However once upon a time I had shipped the database along with my application. It resided in the assets folder and once the application started I copied it in the private application storage (much like any database created with SqliteOpenHelper). From then on I used the usual way with SqliteOpenHelper to access the database.
Basically for this I followed the blog mentioned in this thread and because my database file was bigger than 1MB I used the technique described in this thread. Hopefully combining those two you will get your database running!
EDIT Btw you are wrong, openDatabase does not accept url, but path.