Data definition language, Database Management System

Assignment Help:

Data Definition Language

It organises the data in the form of columns and rows. But what does the data field column of table accumulate? How do you describe it using SQL?

The Data definition language (DDL) defines a set of commands used in the modification and creation of schema objects such as indexes, tables, views etc. These commands give the ability to create, drop and alter these objects. These commands are linked to the management and administrations of the databases. Before and after every DDL statement, the current transactions are implicitly committed, that is changes made by these commands are permanently stored in the databases. Let us talk about these commands in more detail:

CREATE TABLE Command

Syntax:

CREATE TABLE

(

Column_name1 data type (column width) [constraints], Column_name2 data type (column width) [constraints], Column_name3 data type (column width) [constraints],

...............................................

);

Where table name assigns the name of the table, column name describes the name of the field, data type specifies the data type for the field and column width distribute specified size to the field.

 

 

 


Related Discussions:- Data definition language

Define the terms- ddl and dml, Define the terms   i) DDL   ...

Define the terms   i) DDL   ii) DML   DDL: Data base schema is specified by a set of definitions expressed by a special   language known as a data def

Views, what is view?explain

what is view?explain

Data Warehousing Job Scheduling, 1) Define a job scheduling strategy that w...

1) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pict

Which component is not included in database environment, Which component is...

Which component is not included in database environment ? A users component is not included in database environment.

Define an operator that a relational algebra does not have, Define an opera...

Define an operator that a Relational Algebra does not have Ans: Relational Algebra does not have Aggregation operators.

System error-database errors, System error :These contain errors in databas...

System error :These contain errors in database system or the OS, example, deadlocks.Such errors are fairly hard to detect and need reprogramming the erroneous components of the sys

What is a primary key, What is a primary key? Primary key is chosen by ...

What is a primary key? Primary key is chosen by the database designer as the principal means of identifying an entity in the entity set.

What is a shadow copy scheme, What is a shadow copy scheme? It is simpl...

What is a shadow copy scheme? It is simple, but efficient, scheme known as the shadow copy schemes. It is based on making copies of the database called shadow copies that singl

What is a records management consultation, What is a records management con...

What is a records management consultation? Our organization is an authority for disseminating your specific requirements and giving you with a solution to effectively manage yo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd