Failed to open Database Android Java SQLite

Here is my code:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    SQLiteDatabase.openOrCreateDatabase("/gregpeck.db", null);

}

Obviously this is inside my Main Activity.

I have also added the permission to my Main Activity:

    <manifest xmlns:android="http://ift.tt/nIICcg"
        package="ie.callanan.dennis.testhw" >

        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

        <application
            android:allowBackup="true"

The error message I receive is:

Failed to open database 'gregpeck.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database