Dm. Arapov wrote:
> Jan Hidders wrote:
>>Dm. Arapov wrote:
>>>Jan Hidders wrote
>>>>[...]
>>>>So can you statically type the set union?
>>>
>>>Pardon me, I do not understand the question.
>>
>>If I call union(A,B) this should preferrably only be well typed if A and B
>>have the same type. Is this decided at compile time?
>
> Sure. RTL checks if a relational operation is valid in compile-time. All
> checks and schema computations are done in comile-time. In compile
> time we calculate list of colums of result, sort order, check if
> colums, on which relation is sorted, make a key.
So dynamic queries are out of the question - or have to be resolved by
compiling new code and then either dynamically loading the new code or
running a new program? And you cannot write a generic query program
that can be run against any tables in any database without either
prior knowledge of what is in the database or access to a compiler?
--
Jonathan Leffler #include <disclaimer.h>
Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com
Guardian of DBD::Informix 1.00.PC2 -- http://dbi.perl.org/
Received on Sat Nov 02 2002 - 23:16:11 CST
