Unit 1

• How to insert data, modify & Delete in DBMS

  • By using alter we can modify data

    

  • Alter table drop do delete whole coloum

    

  • Updating Data

    

Procedure are rules to perform an action and function are use to compute a value .

• Creating a procedure :

  

  • Syntax

    

    

    

    

• Parameters mode for PL/SQL:

  

  

• Questions

  1. Write a procedure to display your name

  

• Definition:

  It is a set of actions which get executed automatically when specified change operation ( SQL insert, update or delete statement) is performed on perticular table.

  Triggers is used to perform set of actions which get executed automatically where a specified changed operation (insert , update and delete) is performed on perticular table its is performed and generate data automatically, it validated input data, it repeated data with different files to achieve data consistency .

• We can write the file with the perticular purpose.

• How to create triggers

  Each triggers has distinct features

  1. Distinct name :User can use distinct name for trigger in the data base

  2. Table : it specifies the name of table every trigger we examined only a single table .

  3. When the trigger occurs you can use triggers before or after and insertion, deletion or updation of data base to alter triggers data before can be used after trigger must be used with the following

  4. Triger body : It contains group of SQL statement

  5. Syntax of trigger : Click Here

  6. Trigger name comes after create table statement then you need to define after word after keyword is used to process action after the changes made in the table and before if you want to process the action .

  7. Trigger_event : May insert update or delete .

• What are the advantages of triggers 👇:

  

• Syntax to create triggers 👇:

  

  

  

Oracle trigger events :

• Create the trigger to update the records and to set a marks to 100 & the minimum range is 0

  

  

• Write a arithmetic program fro addition