Understanding SQL

SQL Statement Categories

�Data Definition Language (DDL) - �Statements used for creating tables, relationships, and other structures. �Data Manipulation Language (DML) - �Statements used for querying, inserting, modifying, and deleting data. �SQL / Persistent Stored Modules (SQL/PSM) - �These statements extend SQL by adding the ability to do procedural programming, including the use of variables and flow-of-control statements. �Transaction Control Language (TCL) - �Statements that control transaction behavior. �Data Control Language (DCL) - �Statements that grant or revoke permissions to users and groups so that those users and groups can perform operations on the database.

SQL - Framework

�This is the most basic form of SQL queries. � SELECT:  Selects the columns to be listed in the results of the query.�� FROM:  Specifies the tables to be used in the query.� WHERE: Specifies the rows that should be included in the results of the query.��