Android Sqlite Exception. Unable To Instantiate Activity

When I run an activity in my Android app with instantiating dbs classes as follows: private final DbOpenHelper dbOpen = new DbOpenHelper(MainMonitor.this); private final SQLiteDat

Solution 1:

The Activity is created only after onCreate calling. So when you are calling private final DbOpenHelper dbOpen = new DbOpenHelper(MainMonitor.this); activity still not created. Remove final modifier from your db option and init it in separate method after onCreate calling.

You should do smth like this:

publicclassMainMonitorextendsActivity {
private DbOpenHelper dbOpen;
private SQLiteDatabase db;
private ContentValues cv;

@OverrideprotectedvoidonResume() {
    super.onResume();

    initDb();
}

privatevoidinitDb() {
    dbOpen = newDbOpenHelper(MainMonitor.this);
    db = dbOpen.getWritableDatabase();
    cv = newContentValues();
}

//....your code

}

Solution 2:

You are getting a null pointer exception probably in the onCreate - i dont understand the INSERT INTO network(activity) - surely its just INSERT INTO network - you do insert into table name

But that is not how you are meant to do an insert either - use this example

db = this.getWriteableDatabase();
ContentValuesinsertValues=newContentValues();
insertValues.put("Description", "Electricity");
insertValues.put("Amount", 500);
insertValues.put("Trans", 1);
insertValues.put("EntryDate", "04/06/2011");
db.insert("CashData", null, insertValues);

Solution 3:

First you can check without inserting. If database is created then you can test to insert. check data folder, database is created or not.

Solution 4:

I believe this is the line giving you trouble:

sqliteDb.execSQL("INSERT INTO network(activity) VALUES(1)");

Try,

ContentValuesv=newContentValues();
v.put(ACTIVITY, 1);
sqliteDb.insert(TABLE_NAME, null, v);

Make sure you don't insert an empty ContentValues object or else an exception will be thrown.

Solution 5:

your error lies in this line

sqliteDb.execSQL("INSERT INTO network(activity) VALUES(1)");

since you are trying to refer to the activity column in your table, you should surround it with quotes. It should be like this

sqliteDb.execSQL("INSERT INTO network(\"activity\") VALUES(1)");

or

sqliteDb.execSQL("INSERT INTO network(" + ACTIVITY + ") VALUES(1)");