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

What are the causes of bucket overflow in a hash file, What are the causes ...

What are the causes of bucket overflow in a hash file organization? What can be done to reduce the occurrence of bucket overflow? When a record is inserted, the bucket to that

Mapping, external and internal mapping with examples

external and internal mapping with examples

Identify the candidate keys, Consider the following six relation schemes an...

Consider the following six relation schemes and their corresponding sets of functional dependencies. In each case identify a. All the candidate keys b. The highest normal for

Improved performance, Improved performance: As the data is located near the...

Improved performance: As the data is located near the site of its demand, and given the inherent parallelism because of multiple copies, speed of database access may be good for di

Sorting field groups we cannot use more than one key field, While sorting f...

While sorting field groups we cannot use more than one key field False.

Software failures-database recovery and security, Software failures :  In s...

Software failures :  In such cases, a software error abruptly stops the implementation of the current transaction (or all transactions), therefore leading to losing the state of pr

What is the aim of logical schema, What is the aim of logical schema ? ...

What is the aim of logical schema ? The main motive of the logical schema is to ensure the portability of procedures and models on various physical schemas at runtime.

How do you find the final model after iterative analysis, How do you find t...

How do you find the final model after iterative analysis? Why is iterative analysis of any of the problem needed? The final model serves as the base for system architectur

Explain saving derived attributes to avoid re-computation, Saving Derived A...

Saving Derived Attributes to Avoid Re-computation   As discussed, "redundancy means duplication of exact data". But, if multiple copies of same data are present in the system,

Describe entity referential integrity and integrity, Describe entity refere...

Describe entity referential integrity and integrity. Give an example of each. Entity Integrity Rule - If there is a attribute A of relation R is a prime attribute of R then 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