ProviderWithUnion.java

static private class TaskUnionRepeatQuery implements TaskQuery
    {
        @Override
        public Cursor query(SQLiteOpenHelper openHelper,
                            Uri url,
                            String[] projectionIn,
                            String selection,
                            String[] selectionArgs,
                            String sort)
        {
            if (projectionIn.length % 2 != 0)
                throw new IllegalArgumentException("Not a multiple of 2. Are you using the right projection?");

            SQLiteDatabase db = openHelper.getReadableDatabase();

            String taskQuery = "";
            taskQuery += "SELECT ";
            //first half of projection arguments are for task table
            for(int i=0; i<projectionIn.length / 2 - 1; ++i)
            taskQuery += projectionIn[i] + ",";
            taskQuery += projectionIn[projectionIn.length / 2 - 1];
            //end of selection
            taskQuery += " FROM ";
            taskQuery += TASK_TABLE;
            taskQuery += " WHERE ";
            taskQuery += TaskCol.TASK_REPEAT_TYPE+"=0";
            if (selection != null)
            {
                taskQuery += " AND ";
                taskQuery += selection;
            }

            String repeatQuery = "";
            repeatQuery += "SELECT ";
            //second half of projection arguments are for repeat table
            for(int i=projectionIn.length / 2; i<projectionIn.length - 1; ++i)
            repeatQuery += projectionIn[i] + ",";
            repeatQuery += projectionIn[projectionIn.length - 1];
            //end of selection
            repeatQuery += " FROM ";
            repeatQuery += TASK_TABLE+","+REPEATABLE_TABLE;
            repeatQuery += " WHERE ";
            repeatQuery += TaskCol.TASK_REPEAT_TYPE+">0";
            if (selection != null)
            {
                repeatQuery += " AND ";
                repeatQuery += selection;
            }

            String rawQuery = "";
            rawQuery += taskQuery+" UNION "+repeatQuery;
            rawQuery += " ORDER BY " + sort;

            String[] newSelectionArgs = null;
            if (selectionArgs != null)
            {
                newSelectionArgs = new String[2*selectionArgs.length];
                int len = 0;
                for(String selectionArg:selectionArgs)
                    newSelectionArgs[len++] = selectionArg;
                for(String selectionArg:selectionArgs)
                    newSelectionArgs[len++] = selectionArg;
            }
            return db.rawQuery(rawQuery, newSelectionArgs);
        }
    }