Multiple values in one attribute?

Asmaa · #1 (**permalink**) 12-06-11, 14:41

Hi
I know an attribute can only have one value. If for instance a customer in CUSTOMER table has more than one address or telephone number, how I can determine it before defining the attribute of the entity type? What would the source code of it be?

Code:

CREATE TABLE CUSTOMER
(
C_Id CHAR(10),
Name VARCHAR,
Tel_No VARCHAR /*how should I do it? */
);
INSERT INTO CUSTOMER
VALUES (
	'a12',
	'Middin',
	'09182343543 and 033334548934 how should I do it?'
	)

shammat · #2 (**permalink**) 12-06-11, 15:19

Storing multiple values in a single column is considered bad DB design.

However if you really want to do it, you can use an array datatype:

Code:

CREATE TABLE customer
(
   C_Id   VARCHAR(10),
   Name   VARCHAR,
   Tel_No VARCHAR[]
);

INSERT INTO CUSTOMER
(c_id, name, tel_no)
VALUES 
(	'a12',
	'Middin',
	ARRAY ['09182343543','033334548934']
)

Note that you do not want CHAR(10) unless your values are always exactly 10 characters long.

Asmaa · #3 (**permalink**) 12-07-11, 05:59

Thank you
In fact it cause me a lot of difficulty, but I have do deal with it.

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