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

Hardware failure-database recovery and security, Hardware failure : Hardwa...

Hardware failure : Hardware failures are the failures when some disk or hardware chip fails. This may result in loss of data. One such trouble can be that a disk gets damaged and

Data base administrator, What is the role of a database administrator?

What is the role of a database administrator?

What is the difference between where and having clauses, What is the differ...

What is the difference between WHERE and HAVING clauses?. Predicates in the WHERE clause applies to every tuple while the predicate in the HAVING clause applies to groups.

Define single value and multivalued attribute, Define Single Value and Mult...

Define Single Value and Multivalued attribute Single value attribute comprise a single atomic value for an entity and multivalued attribute may have much more than one value f

Sql, sql is relationally complete-justify

sql is relationally complete-justify

What is object containment, What is object containment? References amon...

What is object containment? References among objects can be used to model dissimilar real-world concepts.

Define ssn of salesman by using database of business trips, Consider the su...

Consider the subsequent relations for a database which keeps track of business trips of salespersons in a sales office: SALESPERSON (SSN, Name, start_year, Dept_no) TRIP (SSN, Fr

Explain how the binary tree, QUESTION (a) Give two advantages of using ...

QUESTION (a) Give two advantages of using Linked List as compared to arrays. (b) (i) You are working as programmer at the Orange Mauritius branch. You have been asked to cre

What is asterisk in sql, What is Asterisk in SQL? Asterisk (*): In SQL,...

What is Asterisk in SQL? Asterisk (*): In SQL, the columns for all the tables and views in the FROM clause will be displayed.

Mis, explain various steps uses in evaluation and maintenance of MIS.

explain various steps uses in evaluation and maintenance of MIS.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages

Alter table command, Database Management System

Related Discussions:- Alter table command

Hardware failure-database recovery and security, Hardware failure : Hardwa...

Data base administrator, What is the role of a database administrator?

What is the difference between where and having clauses, What is the differ...

Define single value and multivalued attribute, Define Single Value and Mult...

Sql, sql is relationally complete-justify

What is object containment, What is object containment? References amon...

Define ssn of salesman by using database of business trips, Consider the su...

Explain how the binary tree, QUESTION (a) Give two advantages of using ...

What is asterisk in sql, What is Asterisk in SQL? Asterisk (*): In SQL,...

Mis, explain various steps uses in evaluation and maintenance of MIS.

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