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

Clinic, Need a sample of a clinic database relationships

Need a sample of a clinic database relationships

Creating views with check option-data control, Creating views with check op...

Creating views with check option : This option limits those updates of data values that cause records to go off the view. The following instance tells this in more detail: Examp

Creation of indexes, Creation of Indexes Automatically: When a primar...

Creation of Indexes Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically. Manually: User can

Data warehouse, 1) Define a job scheduling strategy that will meet business...

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

Conversion of er diagram to relational database, Conversion of entity sets:...

Conversion of entity sets: I)   For  every  strong  entity  type  E  in  the  ER  diagram,  we  make  a  relation  R containing all the easy attributes of E. The relation R pri

Explain how the object classes are mapped to tables, Explain how the object...

Explain how the object classes are mapped to tables. Each object class maps to one or more than one tables in the database. The objects in the class may be partitioned horizont

Create student db and execute insert query, Create Student DB and execute I...

Create Student DB and execute Insert query? STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (section identifier, course

Database problem in wordpress, Project Description: I am having a random...

Project Description: I am having a random problem with my Wordpress site. If I click on "Publish" and "Add new", it takes me to a 404 page not found of /wp-admin/post.php (th

Decomposition, properties of derirable decomposition

properties of derirable decomposition

What are the two methods for dealing deadlock problem, What are the two met...

What are the two methods for dealing deadlock problem? The two procedures for dealing deadlock problem is deadlock detection and deadlock recovery.

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