Oracle & SQL Introduction

Database Concepts Revision DB? DBMS? DB Application? Application Programs? DBS? Examples of DBS? Examples of DBMS? 2Oracle & SQL

Database Design Revision Steps in building a database for an application: 1. Analysis:  Understand real-world domain being captured. 2. Design:  Specify it using a database conceptual model (ER).  Translate specification to model of DBMS (Relational or tables). 3. Implementation (using DBMS):  Create schema using DBMS commands (DDL).  Load data (DML). 3Oracle & SQL

Relational Database  A relational database is a DB that stores the data in the form of tables/relations with rows and columns. Every table shares at least one column with another table (Relationships).  A table/Relation is the category of data, like Staff. The columns are information about the category (Attributes), like name or address and the rows are the actual data or records. Oracle & SQL4

Oracle  Oracle is a powerful relational database management system (RDBMS) that offers a large feature set.  Oracle is widely regarded as one of the popular full-featured database systems on the market today.  In almost all relational databases, data is accessed through Structured Query Language (SQL), and Oracle is one of them.  SQL is nonprocedural language that represents a combination of DDL and DML. Oracle & SQL5

Data Definition Language (DDL)  DDL is a descriptive language for defining the database schema.  Some of the main SQL-DDL commands are: CREATE TABLE ALTER TABLE DROP TABLE 6Oracle & SQL

Data Manipulation Language (DML)  DML is a language for retrieving and updating (insert, delete, & modify) the data in the DB.  The main SQL-DML commands are: SELECT INSERT INTO UPDATE DELETE FROM 7Oracle & SQL

Simple Queries Syntax: SELECT { * | column | column_expression [,…] } FROM table_name; Staff 8Oracle & SQL

Simple Queries Retrieve all columns & rows Example: Retrieve all staff information. SELECT sno, fname, lname, position, sex, dob, salary, bno FROM staff; OR SELECT * FROM staff; 9Oracle & SQL

Simple Queries Retrieve specific columns & all rows Example: List salaries of all staff, showing only the staff number, the full and last name, and salary. SELECT sno, fname, lname, salary FROM staff; 10Oracle & SQL

Simple Queries Row selection (WHERE clause) Syntax: SELECT { * | column | column_expression [,…] } FROM table_name WHERE condition; Comparison operators: =,, =, <> 11Oracle & SQL

Example: List all staff with a salary greater than 10,000. SELECT sno, fname, lname, salary FROM staff WHERE salary > 10000; 12Oracle & SQL Simple Queries Row selection (WHERE clause)

Demo Demo Oracle 10g (SQL worksheet)

Oracle & SQL14  From Start menu choose: All Programs  Oracle-OraClient10g_home1  Application Development  SQLPlus Worksheet.

Oracle & SQL15  A DOS window will open (Don't close it) and a login window.  In the login window type S then your serial# then _ then your lecture section# as the Username & password.  In the Service field type O10G then press OK.

Oracle & SQL16  The worksheet window will open. Make sure that “Connected” word is written in the lower panel.

Oracle & SQL17  Disconnect icon: connect/disconnect from server.  Execute icon: execute a SQL statement (as shown below).

Oracle & SQL18  Command History icon: show the SQL Command executed during this session.  Previous/Next Command icon: show the previous/Next SQL statement (Undo/ Redo).

Try your account and execute a simple query.