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

Data fragmentation, Data Fragmentation "Fragmentation includes decompos...

Data Fragmentation "Fragmentation includes decomposing the data in relation to non-overlapping component relations". Why do we require fragmenting a relation?

3NF Normalization, Need 2 projects completed in 3NF format.

Need 2 projects completed in 3NF format.

View of data, how to submit answers softcopy

how to submit answers softcopy

Complexity- drawbacks of data distribution, Complexity : A distributed DBMS...

Complexity : A distributed DBMS that is available, reliable, and secure is inherently more difficult than a centralised DBMS. Though, adequate data replication is essential to have

Differance between open addressing and chaining collision, Differance betwe...

Differance between Open addressing and chaining for collision resolution ? In open addressing , proceeding from the occupied position specified by hash address the program che

Explain the lock based protocol, Lock Based Protocol A lock is nothing ...

Lock Based Protocol A lock is nothing but a mechanism that tells the DBMS whether a particular data item is being used by any transaction for read/write purpose. As there are t

Deadlock and its prevention, Deadlock And Its Prevention: As seen earlier,...

Deadlock And Its Prevention: As seen earlier, though two phase locking protocol handles the trouble of serialisability, but it causes some troubles also. For instance, consider th

Triggers and Stored Procedures, 10A.53 Code an Oracle Database trigger to e...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the delet

Describe difference between a one-to-many and a many-to-many, Describe the ...

Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?

State the meaning of object representation, State the meaning of Object Rep...

State the meaning of Object Representation  The term object representation means "to represent object with the help of objects model symbols". Implementing objects is too simp

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