I am building a test database to understand how constraints / triggers / & foreign keys work...
I have a table called 'zooproducts' and in that table, I have:
Now mainly trying to focus on size of each board. I don't want someone adding in bogus values for 'size' field. I want to make sure that the sizes are only of those in which I offer:
34", 35", 36", 38", 40", 42", 44", & 46" long decks.
Now how can I enforce that only valid values are input into the table. I don't want someone entering 200" deck since that value is obviously bogus. Can someone please help me engineer a way I can enforce the available size options above when entering values into my 'public.zooproducts.size' field?
Not sure if I need a trigger (which I've never used or done before) or if I should create a separate table called 'zoosizes':
and then make some kind of FOREIGN KEY from zooproducts.size > zoosizes.sizes.
Can someone please recommend the best / easiest way to engineer a simple problem in ANSI SQL on how I can force customers / users to enter the correct sizes for my decks that exist versus a value of -32768 to +32767.
Thank you so much!
I have a table called 'zooproducts' and in that table, I have:
Code:
zoo=# \d zooproducts
Table "public.zooproducts"
Column | Type | Modifiers
---------+------------------------+----------------------------------------------------------
id | integer | not null default nextval('zooproducts_id_seq'::regclass)
model | character varying(20) | not null
color | character varying(10) | not null
size | smallint | not null
comment | character varying(100) |
Indexes:
"zooproducts_pkey" PRIMARY KEY, btree (id)
"zooproducts_model_key" UNIQUE CONSTRAINT, btree (model)34", 35", 36", 38", 40", 42", 44", & 46" long decks.
Now how can I enforce that only valid values are input into the table. I don't want someone entering 200" deck since that value is obviously bogus. Can someone please help me engineer a way I can enforce the available size options above when entering values into my 'public.zooproducts.size' field?
Not sure if I need a trigger (which I've never used or done before) or if I should create a separate table called 'zoosizes':
Code:
zoo=# \d zoosizes
Table "public.zoosizes"
Column | Type | Modifiers
--------+----------+-------------------------------------------------------
id | integer | not null default nextval('zoosizes_id_seq'::regclass)
sizes | smallint | not null
Indexes:
"zoosizes_pkey" PRIMARY KEY, btree (id)
zoo=# SELECT * FROM zoosizes ORDER BY id;
id | sizes
----+-------
1 | 34
2 | 35
3 | 36
4 | 37
5 | 38
6 | 40
7 | 42
8 | 44
9 | 46
(9 rows)Can someone please recommend the best / easiest way to engineer a simple problem in ANSI SQL on how I can force customers / users to enter the correct sizes for my decks that exist versus a value of -32768 to +32767.
Thank you so much!