* Ken Tozier [EMAIL PROTECTED] [2004-10-17 00:25:07 -0400]:
So, assuming there's no quantity field defined in the cart table,
if 3 apples, 2 oranges and 1 head of lettuce were purchased on a
specific shopping trip, I would do something like this?
If you need a quantity field, add one.
* Steven Klassen [EMAIL PROTECTED] [2004-10-17 01:52:47 -0700]:
xinu= select * from items_types_view;
id | item_name | type_name
+---+---
1 | Apple | fruit
2 | Orange| fruit
3 | Brocolli | fruit
4 | Lettuce | fruit
(4 rows)
And after I fixed the
Thanks again Stephen
It helps to see a problem you understand defined in a language you
don't. I've got a handhold now.
Ken
On Oct 17, 2004, at 4:52 AM, Steven Klassen wrote:
* Ken Tozier [EMAIL PROTECTED] [2004-10-17 00:25:07 -0400]:
So, assuming there's no quantity field defined in the cart
I'm a C/Objective C programmer and am having a bit of difficulty
figuring out how to define SQL table approximations to things that are
very easy to do in C/Objective C
Basically what I'm confused about is how to simulate arrays of structs
in Postgres. For example, if I define a C struct like
* Ken Tozier [EMAIL PROTECTED] [2004-10-16 13:50:37 -0400]:
I'm a C/Objective C programmer and am having a bit of difficulty
figuring out how to define SQL table approximations to things that
are very easy to do in C/Objective C
I sympathize; no matter how many languages you know, there's
* Steven Klassen [EMAIL PROTECTED] [2004-10-16 17:42:17 -0700]:
INSERT INTO grocery_items (grocery_types_id, name, price) VALUES (1, 'Apple',
'0.50');
INSERT INTO grocery_items (grocery_types_id, name, price) VALUES (1, 'Orange',
'0.75');
INSERT INTO grocery_items (grocery_types_id,
Stephen,
Thanks that does help. Syntax is a bit foreign still. I'm not sure why
you defined the grocery_items_id_exists and grocery_types_id_exists
constraints though. Is that something that's ever explicitly accessed
either through a query or an insert? Or is it one of those things that
* Ken Tozier [EMAIL PROTECTED] [2004-10-16 22:52:10 -0400]:
Or is it one of those things that enforces data integrity behind the
scenes?
That's exactly it -- one of the most attractive things about the
database is that if constraints are defined appropriately it can
defend itself from the
You can track whatever information you need about the particular trip,
add rows to the cart associating the trip with the items being
purchased, and finally the grocery types and items.
CREATE TABLE trips (
id bigserial primary key NOT NULL,
created timestamp default now() NOT NULL
);
