dependent spinner with sqlite isn't working - android-studio

Question

`I'm trying to create a dependent spinner with data from sqlite on android studio. But the spinners isn't showing any content as intended. The Prefix is suppose to narrow down the selection for the Lotno and finally display the Plantation_name based on database SmartSawit.db. pls help :> (its been days)
Spinner spinnerPrefix, spinnerLotno, spinnerPlantation_name;
Context context;
database Database;
String prefixValue, lotnoValue, nameValue;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_daftar_pokok);
spinnerPrefix = findViewById(R.id.spinnerPrefix);
spinnerLotno = findViewById(R.id.spinnerLotno);
spinnerPlantation_name = findViewById(R.id.spinnerPlantation_name);
context = this;
Database = new database(this, "SmartSawit.db", 1);
try {
Database.CheckDB();
fillSpinner(context,spinnerPrefix, "registered_plantation", "prefix", "");
spinnerPrefix.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
prefixValue = parent.getItemAtPosition(position).toString();
fillSpinner(context,spinnerLotno,"registered_plantation","lotno","where prefix = '"+prefixValue+"'");
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
spinnerLotno.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
lotnoValue = parent.getItemAtPosition(position).toString();
fillSpinner(context,spinnerPlantation_name,"registered_plantation","plantation_name","where prefix = '"+prefixValue+"' and lotno ='"+lotnoValue+"'");
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}catch(Exception e){
e.printStackTrace();
}
}
#SuppressLint("Range")
private void fillSpinner (Context context, Spinner mSpinner,String table, String column, String where) {
SQLiteDatabase db = Database.OpenDatabase("registered_plantation.db");
ArrayList<String> mArray = new ArrayList<>();
Cursor cursor = db.rawQuery("Select distinct "+column+" from "+table+""+where, null);
while (cursor.moveToNext()){
mArray.add(cursor.getString(cursor.getColumnIndex(column)));
}
cursor.close();
db.close();
ArrayAdapter mAdapter = new ArrayAdapter(context, android.R.layout.simple_spinner_item,mArray);
mAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mSpinner.setAdapter(mAdapter);
}
}
my databasehelper code:
private Context context;
private static final String DATABASE_NAME = "SmartSawit.db";
private static final int DATABASE_VERSION = 1;
private static final String TABLE_NAME = "registered_plantation";
//private static final String COLUMN_NO = "_no";
private static final String COLUMN_NAME = "plantation_name";
private static final String COLUMN_PREFIX = "prefix";
private static final String COLUMN_LOT_NUMBER = "lotno";
String DbPath;
Context mcontext;
String DbName;
public database(Context context, String name, int version) {
super(context, DATABASE_NAME, null, version);
this.context = context;
this.mcontext = context;
this.DbName = DATABASE_NAME;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
this.DbPath = context.getFilesDir() + "/database/";
}
}
#Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_NAME +
" (" + COLUMN_NAME + " TEXT PRIMARY KEY, " +
COLUMN_PREFIX + " TEXT, " +
COLUMN_LOT_NUMBER + " INTEGER);";
db.execSQL(query);
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public void CheckDB(){
SQLiteDatabase checkDB = null;
String filePath = DbPath + DbName;
File file = new File(filePath);
if(file.isFile() && file.exists()){
Toast.makeText(mcontext, "already exist", Toast.LENGTH_SHORT).show();
} else {
CopyDatabase();
}
}
private void CopyDatabase(){
try {
InputStream ios = mcontext.getAssets().open(DbName);
File directory = new File(DbPath);
if(!directory.exists()){
directory.mkdirs();
}
OutputStream os = new FileOutputStream(DbPath + DbName);
byte[] buffer = new byte[1024];
int len;
while((len = ios.read(buffer)) >0) {
os.write(buffer,0, len);
}
os.flush();
ios.close();
os.close();
Log.d("CopyDb", "Databse Copied");
} catch (Exception e) {
e.printStackTrace();
}
}
void addLadang (String prefix, String namaLadang, int lotNo){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(COLUMN_PREFIX, prefix );
cv.put(COLUMN_NAME, namaLadang );
cv.put(COLUMN_LOT_NUMBER, lotNo );
long result = db.insert(TABLE_NAME,null, cv);
if (result == -1){
Toast.makeText(context, "FAILED", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(context, "SUCCESSFULLY SAVED", Toast.LENGTH_SHORT).show();
}
}
Cursor readAllData(){
String query = "SELECT * FROM " + TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = null;
if(db != null){
cursor = db.rawQuery(query, null);
}
return cursor;
}
public SQLiteDatabase OpenDatabase(String dbName){
String filePath = DbPath + dbName;
return SQLiteDatabase.openDatabase(filePath,null,0);
}
}

Answer 1

You have a number of issues (not actually with the spinners).
First you are trying to open a non-existent database. That is you are using the the table name not the database name in the fillSpinner method by using:-
SQLiteDatabase db = Database.OpenDatabase("registered_plantation.db");
i.e. the database name is SmartSawit.db not registered_plantation.db.
The following fixes that issue (SEE EMBEDDED COMMENTS):-
SQLiteDatabase db = Database.OpenDatabase(/*"registered_plantation.db"<<<<<<<<<<< TABLE NAME NOt DATABASE NAME so USED >>>>>>>>>>*/ database.DATABASE_NAME /*after making it public */);
You then have issues with missing spaces in the WHERE clauses again in the fillSpinner method (fixed using, again see comments):-
Cursor cursor = db.rawQuery("Select distinct "+column+" from "+table+" "/*<<<<<<<<<< ADDED SPACE*/+where, null);
Applying the above fixes and using a layout that has the 3 spinners side by side and with different coloured backgrounds and with an excessive height. And with the following data in the database (in the assets folder name SmartSawit.db):-
Then when first run:-
Clicking on the first spinner
i.e. A and B, the 2 prefixes are selected accordingly
Clicking on B and
i.e. as expected
and so on.
Additional
If you checked the log with your original code, even though it doesn't crash you could have spotted the issue e.g. the log would have included:-
2023-02-07 11:13:59.641 24792-24792/a.a.so75365360javasqlitespinners D/CopyDb: Databse Copied
2023-02-07 11:13:59.642 24792-24792/a.a.so75365360javasqlitespinners E/SQLiteLog: (14) cannot open file at line 36667 of [c255889bd9]
2023-02-07 11:13:59.642 24792-24792/a.a.so75365360javasqlitespinners E/SQLiteLog: (14) os_unix.c:36667: (2) open(/data/user/0/a.a.so75365360javasqlitespinners/files/database/registered_plantation.db) -
2023-02-07 11:13:59.643 24792-24792/a.a.so75365360javasqlitespinners E/SQLiteDatabase: Failed to open database '/data/user/0/a.a.so75365360javasqlitespinners/files/database/registered_plantation.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14 SQLITE_CANTOPEN): Could not open database
at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:211)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:195)
at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:503)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:204)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:196)
at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:880)
at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:865)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:766)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:714)
at a.a.so75365360javasqlitespinners.database.OpenDatabase(database.java:124)
at a.a.so75365360javasqlitespinners.MainActivity.fillSpinner(MainActivity.java:69)
at a.a.so75365360javasqlitespinners.MainActivity.onCreate(MainActivity.java:36)
So although the copy was successfully accomplished e.g. using Device Explorer you would something along the lines of:-
Thus it is easy to see that registered_plantation.db is not at the expected location but SmartSwait.db is.
In short. If using try/catch and things are not working as expected the Check the Log for what you expect to see in the log (e.g. looking for Database copied would have made it easy to see that things were not as expected as the error lines immediately follow that message).