Re: building Oracle database model with ERwin - NOT NULL columns

In Oracle it's totally equivalent if you

CREATE TABLE my_tab
(
 some_column VARCHAR2(100)
);

or if you

CREATE TABLE my_tab
(
 some_column VARCHAR2(100) NULL
);

so ERwin's behaviour to explicitly declare the column as NULLable will do you no harm.

Hint:
http://webboard2.iland.com/~ERwin

On 7 Apr 2002 11:28:27 -0700, gresmi_at_yahoo.com (Greg) wrote:

>I'm hoping someone can help me with a question I have
>about ERwin and Oracle. I've used the ERwin tool to some
>extent working on an existing data warehouse
>database, and I'm now working on my first Oracle
>database from scratch. I'm nearing completion of the logical and
>physical model and have generated the sql report a
>couple of times to check progress.
>
>My question is this:
>If I define a column as "NOT NULL", ERwin handles that
>just fine. However, for every other column created,
>ERwin sets it as "NULL". Is that needed? And, if not,
>is there a way to turn that off?
>I'm using ERwin version 3.5 and I have the server set
>as Oracle 8.x.
>
>Thanks in advance for any help.
>
>(example below)
>------------------------------------------------------
>
>CREATE TABLE EMPLOYEE (
> emp_num CHAR(5) NOT NULL,
> first_name VARCHAR2(20) NOT NULL,
> zipcode_id NUMBER(9) NULL,
> middle_name VARCHAR2(20) NULL,
> state_id CHAR(2) NULL,
> last_name VARCHAR2(20) NOT NULL,
> address VARCHAR2(40) NOT NULL,
> city VARCHAR2(25) NULL,
> phone NUMBER(10) NULL,
> emergency_phone_num NUMBER(10) NULL,
> zone_id CHAR(1) NULL,
> notes VARCHAR2(50) NULL,
> restriction_class CHAR(1) NULL
> CONSTRAINT
>restriction_class16
> CHECK
>(restriction_class IN ('P', 'C', 'E')),
> status CHAR(1) NULL
> CONSTRAINT
>employee_status6
> CHECK
>(status IN ('Y', 'N')),
> foreman_flag CHAR(1) NULL
> CONSTRAINT
>restriction_class17
> CHECK
>(foreman_flag IN ('P', 'C', 'E')),
> ytd_dollars_lost NUMBER(12,2) NULL,
> CONSTRAINT XPKEMPLOYEE
> PRIMARY KEY (emp_num),
> CONSTRAINT zipcode_id_emp_fk
> FOREIGN KEY (zipcode_id)
> REFERENCES ZIP_CODE,
> CONSTRAINT state_id_emp_fk
> FOREIGN KEY (state_id)
> REFERENCES STATE
>);
>
>CREATE INDEX XIF10EMPLOYEE ON EMPLOYEE
>(
> zipcode_id
>);
>
>CREATE INDEX XIF8EMPLOYEE ON EMPLOYEE
>(
> state_id
>);

regards
Marc Blum
mailto:marc_at_marcblum.de
http://www.marcblum.de Received on Sun Apr 07 2002 - 14:08:08 CDT