Concept of Inheritance with PostgreSQL

Inheritance in Postgresql 

A table in PostgreSQL can inherit from many tables. A query may include either all rows of a table or all rows of a table including its descendants. The INHERITS clause is used for using Inheritance in PostgreSQL. The child table had all the attributes of the parent table.

Syntax:

CREATE TABLE 
childtable

         INHERITS ( 
parenttable
 [, ...] )

Let's understand the implementation of Inheritance in Postgresql. 

CREATE TABLE billing (
  cust_id text,
  name text,
  item text,
 quantity int,   
);


CREATE TABLE address (
cust_id text,
name text,
cust_address text,
);

CREATE VIEW bill AS
  SELECT cust_id, name , item, quantity FROM billing
    UNION
  SELECT cust_id, name, cust_address FROM address;

In the above approach, if we update the billing table, we need to update the address table separately. This increases the problem of database anomaly.

Let's look at the efficient way of using Inheritance.

CREATE TABLE billing (
  cust_id text,
  name text,
  item text,
 quantity int,   
);


CREATE TABLE address (
cust_address text,
); INHERITS (billing);

In the above approach, if we update the billing table, the corresponding value in the billing table gets updated. This reduces the chances of database anomaly.

The address table will automatically have the attributes of the billing table.

Also read anomalies in database

Frequently Asked Questions

What is the advantage of Inheritance?

The main advantage of Inheritance is code reusability.

What is the difference between the char data type and the varchar data type in PostgreSQL?

The Char data type stores fixed-length characters in a column, whereas the varchar data type stores variable-length characters in a column.

Why is PostgreSQL so widely used?

PostgreSQL is a powerful database management system with numerous sophisticated functionalities and security features. It's also a community-driven database management system that's open-source and free to use.

Conclusion

In this article, we have discussed the details of the Concept of Inheritance with PostgreSQL.

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