Best practice in datatypes

Question

Hello all
I'm new to Oracle (have used other DBMSs) and I'm missing a couple of datatypes, so I'm looking for advice as to how to replace them:
boolean: I will need to handle 3-valued logic (true, false and NULL) directly in SQL syntax, i.e. COALESCE, IN, etc.
cidr/inet: how do you handle IPv4 network addresses? I can think of a CHAR(15) and store it directly as a string, but I would like to be able to operate on it to some extent, i.e. validate network masks, broadcast address, etc. Are there some add-on datatypes/operators to handle this?
TIA,
cl.

Answer 1

For boolean values, you normally define a CHAR(1) (or VARCHAR2(1)) with a CHECK constraint that restricts the values to one of two values, i.e.
CREATE TABLE t (
  bool_col CHAR(1) CHECK( bool_col IN( 'Y', 'N' ) )
)In PL/SQL, you can then use the BOOLEAN data type if you'd like.
For IP addresses, my default would be to declare a VARCHAR2(15) and store the information there. For manipulation, I'd define an IP Address object that would encapsulate whatever IP address logic you want. If you're on 10g, you can also use the regular expression package to define a constraint that ensures a well-formed address.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC