SQL ( Structured Query Language )

SQL is not a single language of its own rather than it is a combination 5 diff. sublanguage. Those are

1. DQL/DRL –Data Query language /Data retrieve language.

Select

2. DDL/OML – Data Definition Lang/Object manipulation Lang

Create
Alter
Drop
Truncate
Rename

3. DML/RML – Data manipulation Lang / Record manipulation Lang

Insect
Update
Delete

4. TCL – Transaction control Lang

5. DCL – Data Control Lang

DQL/DRL:

It is responsible to manipulate to retrieve a data from a table and display to the user. To do so DQL provides a statement called select.

DDL/OML:

DML is responsible to manipulate the object in ORACLE database.
ORACLE provides following objects for customized database management

Table

View
Synonyms
Sequence
Index
Type

To create and manipulate above objects DDL provides the following statements

i. Create
ii. Alter
iii. Drop
iv. Tractate
v. Rename

DML/RML:

It is responsible to manipulate the records of a table. To do so DML provides
The following statements
i. Insert
ii. Update
iii. Delete

TCL:

Any operation is made in an ORACLE. The records never be saved and until a save command is issued or a discard command in issued. To do so TCL provides the following statements.
i. Commit
ii. Rollback
iii. Save point

DCL:

ORACLE support user concepts or schema concept to protect the object from invalid user. To do so DCL provides the following statement
i. Grant
ii. Remove

NOTE:

―Schema is a logical memory which holds some physical object by password‖.

SELECT:

To perform selection ORACLE provides by default 3 diff. tables called

Emp -, dept, salgrade

Above table are available in default user called Scott.

NOTE:

Not only oracle provides us Scott default user rather then it provides another user called system (super user) which is a DBA user or super user.

NOTE:

JOHN LARRY ERISSION was founder of ORACLE.
BRUSH SCOTT was architecture of ORACLE.