Nested classes
От | Ferruccio Zamuner |
---|---|
Тема | Nested classes |
Дата | |
Msg-id | yam7513.2594.137981104@mail.chierinet.it обсуждение исходный текст |
Список | pgsql-sql |
Hi all, I want to define one class as compound object of user defined classes and basic types. something like: CREATE TABLE attributes { Strenght int, Health int, Mana int, Inteligence int }; CREATE TABLE character { Name text, Role text, Damage int, Defense int, Age int, Attributes attributes }; CREATE TABLE player { Name text, Age int, Telephone text, Character character }; This is something like defining a C++ class with other user-defined classes as attributes (no derivation, but containment). Postgres 6.3.1 accepts the definitions above but the problems come when I want to insert records of "player" type. I have the following questions: 1. Is there any syntactic sugar (as { } for arrays) for INSERTing a new "player" including its Character sub-object? 2. what about the same problem using a COPY to populate the DB from ascii file? 3. after eventually having populated the DB, I'd like to write something like: SELECT Character.Name, Character.Attributes.Intelligence FROM player WHERE Age<18 AND Character.Age > 25; to extract the name and intelligence of all the characters older than 25 played by people younger than 18 I know that some form of composite classes can be defined inserting OIDs of sub-objects as attributes but this seems a bit weak and tricky solution. Is there a better one? Thanks in advance Ferruccio
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