D. Richard Hipp wrote:
>
>
> On Sep 5, 2008, at 9:03 AM, paul schindler wrote:
>
>>
>> Hello,
>>
>> I have a virtual table and some (by me) declared datatypes are
>> "TEXT10" or
>> "INTEGER" or "DATE"...
>>
>> When I am using the function sqlite3_column_decltype() then I get
>> those
>> types back, that's great. But I have a problem with aggregate
>> functions.
>> E.g. the field "amount" with the datatype "INTEGER":
>>
>> sqlite3_column_decltype("select amount from myvirtualtable", 0)
>> returns
>> "INTEGER" -> good!
>>
>> BUT:
>>
>> sqlite3_column_decltype("select sum(amount) from myvirtualtable", 0)
>> returns
>> NULL -> very bad!
>>
>> Is there a possibility to get the declared datatype of an aggregate
>> function?
>>
>> Because the function sqlite3_column_type() always returns
>> SQLITE_NULL for my
>> virtual tables...
>
>
> Aggregate functions do not have a declared datatype. Look at the
> interface definition for sqlite3_create_function(). We get to define
> the name of the function, the number of parameters, and the preferred
> text encoding. But there is no place to specify the return datatype.
> Indeed, many aggregate functions (ex: max()) return different
> datatypes depending on the datatypes of their inputs. In your
> example, the sum() function might return either real or integer - it
> returns integer if all arguments are integers and it returns real if
> any input value is a real.
>
>
> D. Richard Hipp
> [EMAIL PROTECTED]
>
>
>
> _______________________________________________
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> sqlite-users@sqlite.org
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>
>
Thanks for your answer!
But I expected that when 'amount' has the declared datatype INTEGER then
sum(amount) is also INTEGER...
Paul
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