unique value in Oracle

Question

I'm new to oracle and I am doing simple exercises to broaden my knowledge I think I did every step successfully besides one.

The question was:

Create a table called Bank, which include following fields: Bank_id which is a number and has length of 5 and is primary key bank_name which is a string with length of 5 and may not be empty and Bank_Address which is a string, has length of 20 and is unique Here's what I wrote

CREATE TABLE Bank
{
Bank_id number(5) primary key,
Bank_name varchar(5) NOT NULL,
 bank_address varchar(20)

}

My question is following How do I declare something as unique? and is rest of my assignment correct? I'm asking you this because I am not able to view correct answer for few days and I'm anxious to know if I did this correctly, excuse my English and thanks.

You might want to read the Oracle tutorial: https://docs.oracle.com/cd/E11882_01/appdev.112/e10766/tdddg_objects.htm#TDDDG32200 — , Nov 09 '14 at 16:34
Oracle recommends using `varchar2` instead of `varchar` for strings. — Gordon Linoff, Nov 09 '14 at 16:41

score 1 · Answer 1 · answered Nov 09 '14 at 16:37

1

You need to add a unique constraint for the field bank_address to be unique like

CONSTRAINT bnk_addr UNIQUE (bank_address)

With that your CREATE TABLE statement should look like

CREATE TABLE Bank
(
Bank_id number(5) primary key,
Bank_name varchar(5) NOT NULL,
bank_address varchar(20),
CONSTRAINT bnk_addr UNIQUE (bank_address)
);

answered Nov 09 '14 at 16:37

Rahul

76,197
13
71
125

1

@user3550204, consider accepting the answer if you have found it helpful. – Rahul Nov 09 '14 at 17:00

unique value in Oracle

1 Answers1