my sqlite android program is not working this function help please find error,

Question

public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DBNAME = "temp.sqlite";
public static String name;
public static final String DBLOCATION = "/data/data/my_packge_name/databases";
public Context mContext;
public SQLiteDatabase mDatabase;
public DatabaseHelper(Context context) {
    super(context,DBNAME,null,1);
    this.mContext=context;
}
@Override
public void onCreate(SQLiteDatabase db) {

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

public void openDatabase(){
    String dbPath = mContext.getDatabasePath(DBNAME).getPath();
    if( mDatabase != null && mDatabase.isOpen() ) {
        return;
    }
    mDatabase = SQLiteDatabase.openDatabase(dbPath, null, SQLiteDatabase.OPEN_READWRITE);

}


public String contentsLoad() {
    openDatabase();
    SQLiteDatabase mDB = mDatabase;
    int sls=1;
    Cursor cursor= mDB.rawQuery("SELECT * FROM my WHERE sl="+sls,null);
    name=new String(cursor.getString(1));
    closeDatabase();
    return name;
}


public void closeDatabase() {
    if (mDatabase!=null) {
        mDatabase.close();
    }
}

}

No data returns.

I thing The Error occured in contentsLoad() function below portion, But Exactly i don't know what is the error

    int sls=1;
    Cursor cursor= mDB.rawQuery("SELECT * FROM my WHERE sl="+sls,null);
    name=new String(cursor.getString(1));

I need return the name string. How is it possible?

An error occurs when I run this function and closed the app

Error occured in this lines .... Cursor cursor= mDB.rawQuery("SELECT * FROM my WHERE sl="+sls,null); name=new String(cursor.getString(1)); — Mohammed Iqbal E, Nov 03 '16 at 14:09
Please [edit] your question. Do not add put errors in the comments — OneCricketeer, Nov 03 '16 at 14:10
It's easy to say it's working fine - but really I'm asking for your audience. Your asking us for help in understanding your code and there are two method calls which are essentially voids in the logic. We need to understand your code to understand how to assist you. — apelsoczi, Nov 03 '16 at 14:10
Is the error that no data is returned or the app crashes because an exception? We can't help without the logcat or a [mcve] — OneCricketeer, Nov 03 '16 at 14:12
Your query should be a string and sls is a int. Try `String.valueOf(sls)` — compte14031879, Nov 03 '16 at 14:15
@FrédéricLetellier, it will be casted to string any way. That's not a problem — Vladyslav Matviienko, Nov 03 '16 at 14:16

score 2 · Answer 1 · answered Nov 03 '16 at 14:15

Error occured in this lines .... Cursor cursor= mDB.rawQuery("SELECT * FROM my WHERE sl="+sls,null); name=new String(cursor.getString(1));

Before reading data from a cursor you need to place it on a valid row:

Cursor cursor= mDB.rawQuery("SELECT * FROM my WHERE sl="+sls,null);
if (cursor.moveToFirst()) {
    name=new String(cursor.getString(1));
}

That would be one reason for the code to crash there. There may be others; start debugging with the stacktrace. Include the stacktrace in questions like this, too.

complete code added , the above is not working – Mohammed Iqbal E Nov 03 '16 at 14:29 — Mohammed Iqbal E, Nov 03 '16 at 14:29

my sqlite android program is not working this function help please find error,

1 Answers1