COMMAND FOR ORACLE SQL

                                     COMMAND FOR ORACLE SQL

                                                        COMMAND FOR ORACLE SQL

CLASSIFICATION OF SQL COMMAND:-

In order to learn sql command we will have to learn various sql command or statement support by sql language.

All the sql command can be broadly classified into five category as given-

·         DQL=DATA QUERY LANGUAGE.

·         DDL=DATA DEFINIATION LANGUAGE.

·         DML=DATA MANIPULATION LANGUAGE.

·         DCL=DATA CONTROL LANGUAGE.

·         TCL=TRANSACTION CONTROL LANUAGE.

DQL=SELECT.

DDL=CREATE, DROP, ALTER.

DML=INSERT, UPDATE, DELETE, TRUNCATE.

DCL=GRANT, REVOKE.

TCL=COMMIT, ROLLBACK, SAVEPOINT.

DQL=DATA QUERY LANGUAGE:-

These command are used to view record from table onto computer screen.

The actual data from in table is stored onto the hard disk of oracle data server and DQL command enable us to view the information or record store in database monitor.

DDL=DATA DEFINATION LANGUAGE:-

DDL statement are used to create tables, remove table and make to the change to the table structure.

Table structure are refer to number of column and data types of column and constraint which can be applied or remove au you wish.

DML=DATA MANIPUATION LANGUAGE:-

DML is used to for adding new record, remove existing record or changing values of existing record we will use DML statement.

DCL=DATA CONTROL LANGUAGE:-

Oracle is multi user database management system.

Each user has his own assign area where his data is store.

TCL=TRANSACTION CONTROL LANGUAGE:-

Each operation which is done on database is called transaction.

Transaction can be addition of new record, modification in values of existing record