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.
The Nazca Lines: A Mystery on the Plains
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In the Peruvian Desert, about 200 miles south of Lima, there lies a plain
between the Inca and Nazca (sometimes also spelled Nasca) Valleys. Across
this...
8 years ago
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