04-01-2013, 03:38 PM
SQL Basics
SQL Basics.pdf (Size: 252 KB / Downloads: 90)
SQL – What Is It?
Structured Query LanguageStructured Language
Common Language For Variety of DatabasesDatabases
ANSI Standard BUTANSI BUT…….
Two Types of SQLTwo SQL
DML ––Data Manipulation Language (SELECT)
DDL ––Data Definition Language (CREATE TABLE)
Pros & Cons of SQL
Pros:
Very flexibleVery flexible
Universal (Oracle, Access, Paradox, etc)
Relatively Few Commands to LearnRelatively Learn
Cons:
Requires Detailed Knowledge of the Structure of the Databaseof Database
Can Provide Misleading ResultsCan Results
Basic SQL Components
SELECT schema.table.columncolumn
FROM table aliasalias
WHERE [conditions]
ORDER BY [columns]
Defines the end of an SQL statementDefines statement
Some programs require it, some do not (TOAD Does Not)
Needed only if multiple SQL statements run in a scriptNeeded script