If you mean that you want the affinity of test1111.fp2 to be real then you can declare the view as:
```
CREATE VIEW test1111
AS SELECT *,
cast(SUM(future_price) as REAL) as fp2
FROM t_spotprice
WHERE tradingday = 20200103;
```
The affinity of the result of an expression (which also includes functions) is NONE (No Affinity). This is quite separate from the datatype of the result value.