مقدمة في PL/SQL

Introduction to PL/SQL

• PL/SQL is Oracle Corporation's procedural programming language for relational databases.
• It extends SQL with procedural logic.
• PL/SQL is a third-generation programming language (3GL).
• PL/SQL combines program logic and control flow with SQL.
• PL/SQL is a standard and portable language for Oracle development.
• It's also a high-performance, highly integrated database language.

Objectives

• Describe PL/SQL.
• Differentiate between SQL and PL/SQL.
• Explain the need for PL/SQL.

Purpose

• To describe the characteristics of PL/SQL and the differences between PL/SQL and SQL.
• To learn how PL/SQL addresses the limitations SQL. This helps understanding the necessity of PL/SQL.

PL/SQL Description

• A procedural language extension to SQL.
• An Oracle proprietary programming language.
• Combines program logic and control flow with SQL.

SQL Description

• A nonprocedural language.
• Also known as a declarative language.
• A fourth-generation programming language (4GL).
• Primarily used to access and modify data in relational databases.
• Standardized by the American National Standards Institute (ANSI).
• Vendors (like Oracle) might include proprietary SQL features in database environments.

SQL Statement

• A simple, straightforward SQL statement.
• Modifying data conditionally in SQL can have limitations.
• Can't easily update data in conditional manners.

Limitations of SQL

• Difficulty with conditional data modifications
• Promoting employees based on tenure and job type.
• Needs multiple SQL statements for each type of job updates , making the task tedious.

Limitations of SQL (Solution)

• One solution for updating job_id data is shown.
• To update multiple job_ids you will need multiple SQL statements.

PL/SQL Extends SQL with Procedural Logic

• Write one statement (PL/SQL) to promote sales representatives, marketing representatives, and stock clerks.
• PL/SQL makes it possible to write one statement to complete a task.

Procedural Constructs

• Use PL/SQL to write procedural code and embed SQL statements.
• Procedural code includes variables, constants, cursors, conditional logic, and iteration.
• PL/SQL code blocks can be saved and named, then executed when needed.

Characteristics of PL/SQL

• Highly structured, readable, and accessible language.
• Standard and portable language for Oracle development.
• Works with SQL as an embedded language.
• High-performance, highly integrated database language.
• Based on the Ada Programming Language with syntax similarities.

Terminology

• Key terms in the lesson: PL/SQL, Procedural Constructs.

Summary

• Learned to describe PL/SQL.
• Differentiated between SQL and PL/SQL.
• Explained the need for PL/SQL.