Alter table command, ALTER TABLE Command : This command is used for variation of existing, Database Management System

Alter table command, Database Management System

Assignment Help:

ALTER TABLE Command: This command is used for variation of existing structure of the table in the given situation:

When a new column is to be added to the table structure.
When the existing column definition has to be altered, i.e., changing the width of the data type or the data type itself.
When integrity constraints have to be dropped or included.
When a constraint has to be allowed or not allowed.

Syntax

ALTER TABLE

ADD ( ...); ALTER TABLE

MODIFY ( ...);

ALTER TABLE

ADD CONSTRAINT < constraint type>(field name);

ALTER TABLE

DROP;

ALTER TABLE

ENABLE/DISABLE ;

You require to put many constraints like that the database integrity is not compromised.

Related Discussions:- Alter table command

Database manegement, how to data store?

how to data store?

Which operations need the participating relations to union, Which operation...

Which operations need the participating relations to be union compatible? A UNION, INTERSECTION and DIFFERENCE operations need the participating relations to be union compatibl

Define single valued and multivalued attributes, Define single valued and m...

Define single valued and multivalued attributes. Single valued attributes: attributes with a single value for a particular entity are known as single valued attributes. Mult

Optimistic concurrency contents -write-set(t), write-set(T): Each data ite...

write-set(T): Each data items that are written by a transaction T

Applications and goals of dbms, What do you mean by DBMS? What is its need ...

What do you mean by DBMS? What is its need and what are its goals. Explain? OR Explain Data Base Management System? Sol. Database management system is a

What are the benefits of decomposing a system, What are the benefits of dec...

What are the benefits of decomposing a system? The benefits of decomposing a system into subsystems are that after decomposition, each individual component become smaller and e

Define the normalisation form, Define in which normalisation form if an att...

Define in which normalisation form if an attribute of a composite key is dependent on an attribute of other composite key. Ans: 3NF A relation is in 3 NF if an attribute of

DML complier, definition and its work

definition and its work

Distributed transaction atomic-consistent-isolated, A distributed transacti...

A distributed transaction consists of subtransactions that execute at different sites and access local DBMSs at those sites. For example, a distributed transaction that transfers m

In e-r diagram how generalization is represented, In E-R diagram how genera...

In E-R diagram how generalization is represented? in E-R diagram generalization is represented by Triangle shape.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages

Alter table command, Database Management System

Related Discussions:- Alter table command

Database manegement, how to data store?

Which operations need the participating relations to union, Which operation...

Define single valued and multivalued attributes, Define single valued and m...

Optimistic concurrency contents -write-set(t), write-set(T): Each data ite...

Applications and goals of dbms, What do you mean by DBMS? What is its need ...

What are the benefits of decomposing a system, What are the benefits of dec...

Define the normalisation form, Define in which normalisation form if an att...

DML complier, definition and its work

Distributed transaction atomic-consistent-isolated, A distributed transacti...

In e-r diagram how generalization is represented, In E-R diagram how genera...

Write Your Message!

Featured Services

Online Tutoring

Project Development

Exam Preparation

Course Help

Assignment Help

Popular Subjects

Assured A++ Grade

Academics

Major Subjects

Majors

Get In Touch

TERMS & POLICIES

HELP & SUPPORT