Android: SQLite Row update causes Nullpointer Exception [duplicate]

This question already has an answer here:

• What is a Null Pointer Exception, and how do I fix it? 12 answers

My SQLite Row Update method causes a NullPointer Exception when trying to update a value.

 public void addLike(DBOps dop, String productid,String newValue,String oldValue)
 {
    try
    {
        ContentValues updatedValues = new ContentValues();
        updatedValues.put(TableInfo.LIKED, newValue); 
        String where="pid = ?";
        updatedb.update(TableInfo.TABLE_NAME,updatedValues, where, 
                                                new String[]{productid});
    }
    catch(Exception e)
    {
        Log.e("UPDATE ERROR", "Couldn't update likes!");
        Log.e("UPDATE ERROR", Log.getStackTraceString(e.getCause()
                                                      .getCause()));
    }
  }

My table name is stated in: TableInfo.TABLE_NAME My column name is stated in: TableInfo.LIKED

Old value is retrieved by a different Get Method. The ProductID and the NewValue is not null. I checked and they contain the proper values. Is my Update method correct?