Data definition language, Database Management System

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.

 

 

 

Posted Date: 3/11/2013 12:54:27 AM | Location : United States







Related Discussions:- Data definition language, Assignment Help, Ask Question on Data definition language, Get Answer, Expert's Help, Data definition language Discussions

Write discussion on Data definition language
Your posts are moderated
Related Questions
Define NULL value NULL value NULL means something is unknown. It does NOT mean null (the digit 0). Null is as well employed as attribute value for a particular entity in which

Physical Database Design Issues The database design includes the process of logical design with the use of E-R diagram, normalisation, etc., followed by the physical design.

Instructions: Follow the instructions below for completing this project: 1. Creating the Database: · Use the physical table descriptions given below to define and create each t

sir we want er diagram of bank management system in this main menu option as new account,deposit amount,withdraw amount,all acount holder list,modify account,close account

Discuss The difference between drop table R and delete from R.  DROP TABLE command deletes all the records with the table definition. This command will automatically committed

System Design: An Object Oriented Approach Any software systems always try to change and evolve as technology and business rules evolve. The development of information systems

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

Developer is required to do a task including: - Database Normalization - Database Analysis - ERM Diagram Details can be provided and then you can change your bid accord

(a)    Provide the description of the following ODMG schema in the Object Definition Language (ODL). (b)   Based on the above object database, write the following queries i

What are stored-procedures? And what are the advantages of using them? Stored procedures are database objects that perform a user defined operation. A stored procedure can have