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

Normalization e, explain normalization,and give the examples 1NF,2NF,3NF,BC...

explain normalization,and give the examples 1NF,2NF,3NF,BCNF.AND FUNCTIONAL DEPANDENACY AND DECOMPOSITION TECHNIQUES.

Describe object relational model, Describe Object Relational model ? O...

Describe Object Relational model ? Object Relational Model - This model combines the characteristics of both relational model and object oriented model. It extends the tradit

Properties of a transaction , Properties of a Transaction        A tra...

Properties of a Transaction        A transaction has four main properties. These are: Atomicity Consistency Isolation or Independence Durability or Permanen

Design of distributed databases, Design Of Distributed Databases: The dist...

Design Of Distributed Databases: The distributed databases are mainly relational at local level. So a local database schema is the similar as that of a centralised database design

Answer, what is database management system? & why it is required?

what is database management system? & why it is required?

What are the various forms of data transparency, What are the various forms...

What are the various forms of data transparency? a) fragmentation transparency b) replication transparency c) location transparency

Adding redundant associations for efficient access, Adding Redundant Associ...

Adding Redundant Associations for Efficient Access Redundant associations do not add any type of information, therefore during design we should actually examine structure of o

In which form of relational database developer refers, In which form of rel...

In which form of relational database developer refers to a record? In a tuple form of relational database developer refers to a record.

Data model in DBMS, how many types of data model in DBMS? explain data abst...

how many types of data model in DBMS? explain data abstraction with its different level

Relation and relational schema, A relation has: Relational Schema ...

A relation has: Relational Schema Relation instance Relational Schema: A relational schema shows the relation's name, its attributes and the domain of every a

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