The main categories are
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DDL (Data Definition Language)
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DML (Data Manipulation Language)
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DQL (Data Query Language)
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DCL (Data Control Language)
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Data administration commands
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Transactional control commands
Defining Database Structures
Some of the most fundamental DDL commands discussed during following hours include the following:
CREATE TABLE
ALTER TABLE
DROP TABLE
CREATE INDEX
ALTER INDEX
DROP INDEX
CREATE VIEW
DROP VIEW
Manipulating Data
There are three basic DML commands:
INSERT
UPDATE
DELETE
Data Control Language
Data control commands in SQL allow you to control access to data within the database. These DCL commands are normally used to create objects related to user access and also control the distribution of privileges among users. Some data control commands are as follows:
ALTER PASSWORD
GRANT
REVOKE
CREATE SYNONYM
Transactional Control Commands
In addition to the previously introduced categories of commands, there are commands that allow the user to manage database transactions.
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COMMIT Saves database transactions
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ROLLBACK Undoes database transactions
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SAVEPOINT Creates points within groups of transactions in which to ROLLBACK
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SET TRANSACTION Places a name on a transaction