Example of sequences, Database Management System

Assignment Help:

Example: Create a sequence named SEQSS that starts at 105, has a step of 1 and can take maximum value as 2000.

 CREATE SEQUENCE SEQSS START WITH 105

INCREMENT BY 1

MAX VALUE 2000;

How the sequence so formed is used? The following sequence of commands try to illustrate the use of the sequence SEQSS.

Suppose a table person exists as: SELECT * FROM PERSON;

Output:             CODE      NAME         ADDRESS

------                      -------    --------         ---------------

                               104       RAMESH    MUMBAI

Now, if we give the command:

INSERT INTO PERSON

VALUES (SEQSS.NEXTVAL, &NAME, &ADDRESS) 

On implementation of statement above do the following input:

Enter value for name: 'Rakhi'

Enter value for address: 'New Delhi'

Now, here is the following command to see the output:

SELECT * FROM PERSON;

CODE        NAME           ADDRESS

--------- --------------- -----------------

104        RAMESH         MUMBAI

105        Rakhi             NEW DELHI

 

The explanations of sequences such as minimum value, maximum value, increment or step are stored in the data dictionary.  For instance, in oracle it is stored in the table user_sequences. You can see the explanation of sequences by giving the SELECT command.


Related Discussions:- Example of sequences

Dirty reads-problems of concurrent transactions, Dirty Reads: T10 reads a ...

Dirty Reads: T10 reads a value which is updated by T9. This update has not been committed and T9 aborts. T9 T10 Value of x old value = 200

Write short notes on schema diagram, Write short notes on Schema diagram. ...

Write short notes on Schema diagram. A database schema along with primary key and foreign key dependencies can be depicted pictorially by schema diagram. Every relation appears

Objectives-distributed and client server databases, Objectives diff...

Objectives differentiate DDBMS and conventional DBMS; Describe Network topology for DDBMS; Describe the concepts of horizontal and vertical fragmentation; Descr

Basic set operation, These are the binary operations; i.e., each is applied...

These are the binary operations; i.e., each is applied to two relations or sets. These two relations can be union compatible excluding in case of Cartesian product. Two relations R

Sub query in the update command, Sub query in the UPDATE command : Exam...

Sub query in the UPDATE command : Example :  //Double  the  commission  for  employees,  who  have  got  at  least  2 increments. UPDATE EMP SET COMM = COMM * 2 WHERE

Describe file organisation, Describe file organisation? A file is organ...

Describe file organisation? A file is organized logically as a sequence of records. These records are mapped onto disk blocks. A) Fixed-Length Records Type deposit=record

Optimistic concurrency contents -write-set(t), write-set(T): Each data ite...

write-set(T): Each data items that are written by a transaction T

Sql iis setup and admin - maybe tfs, I want a good Microsoft Admin experien...

I want a good Microsoft Admin experienced in IIS and SQL Server. They require being able to set it up and administer from then onwards. Experience in Team Foundation Server a

Define database layer, Define Database layer? The database layer define...

Define Database layer? The database layer defines the data formats used in the database.

Explain the hierarchical database model, Problem: (a) Briefly explain t...

Problem: (a) Briefly explain the ‘Hierarchical Database Model' using appropriate diagram. (b) List and briefly describe five potential benefits of the database approach comp

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