SQL( Structure Query Language):
SQL is short for Structured Query Language and is a widely used database language, providing means of data manipulation (store, retrieve, update, delete) and database creation.Almost all modern Relational Database Management Systems like MS SQL Server, Microsoft Access, MSDE, Oracle, DB2, Sybase, MySQL, Postgres and Informix use SQL as standard database language.
Basic SQL Command:
DQL(Data Query Language)
SELECT: Command to retrieve data from tables and views.
DDL: (Data Definition Language):
This includes all commands need to create, modify and drop the structure of database objects.
CREATE: command user to create any database object.
ALTER: command to modify the structure of any database object.
DROP: To remove the object from database dictionary.
DQL(
DML(Data Manipulation Language):
This includes command to insert, update and delete data from tables.
INSERT: To insert a record into table.
UPDATE: To update a particular record.
DELETE: To delete a Record from the table.
DCL(Data Control Language):
Contol the access to data in database.
GRANT to allow specified users to perform specified tasks.
REVOKE to cancel previously granted or denied permissions.
DTL(Data Transaction Language):
Control transactions in database accessCOMMIT: commit (make persistent) all changes for the current transaction
ROLLBACK:-- roll back (rescind) all changes for the current transaction.
Beyond the Event Horizon: Unraveling the Mysteries of Black Holes
-
*Introduction:*
In the vast cosmic tapestry of the universe, there exist enigmas so
profound that they challenge the very fabric of our understanding. ...
1 year ago
0 comments:
Post a Comment