Sams Teach Yourself SQL in 24 Hours

By Ron Plew and Ryan Stephens

• Table of Contents
  • Copyright
  • About the Authors
  • Acknowledgments
  • Tell Us What You Think!
  • Introduction
  • Part I: A SQL Concepts Overview
  • Hour 1. Welcome to the World of SQL
  • Part II: Building Your Database
  • Hour 2. Defining Data Structures
  • Hour 3. Managing Database Objects
  • Hour 4. The Normalization Process
  • Hour 5. Manipulating Data
  • Hour 6. Managing Database Transactions
  • Part III: Getting Effective Results from Queries
  • Hour 7. Introduction to the Database Query
  • Hour 8. Using Operators to Categorize Data
  • Hour 9. Summarizing Data Results from a Query
  • Hour 10. Sorting and Grouping Data
  • Hour 11. Restructuring the Appearance of Data
  • Hour 12. Understanding Dates and Times
  • Part IV: Building Sophisticated Database Queries
  • Hour 13. Joining Tables in Queries
    • Selecting Data from Multiple Tables
    • Types of Joins
    • Join Considerations
    • Summary
    • Q&A
    • Workshop
  • Hour 14. Using Subqueries to Define Unknown Data
  • Hour 15. Combining Multiple Queries into One
  • Part V: SQL Performance Tuning
  • Hour 16. Using Indexes to Improve Performance
  • Hour 17. Improving Database Performance
  • Part VI: Using SQL to Manage Users and Security
  • Hour 18. Managing Database Users
  • Hour 19. Managing Database Security
  • Part VII: Summarized Data Structures
  • Hour 20. Creating and Using Views and Synonyms
  • Hour 21. Working with the System Catalog
  • Part VIII: Applying SQL Fundamentals in Today's World
  • Hour 22. Advanced SQL Topics
  • Hour 23. Extending SQL to the Enterprise, the Internet, and the Intranet
  • Hour 24. Extensions to Standard SQL
  • Part IX: Appendixes
  • Appendix A. Common SQL Commands
  • Appendix B. Using MySQL for Exercises
  • Appendix C. Answers to Quizzes and Exercises
  • Appendix D. CREATE TABLE Statements for Book Examples
  • Appendix E. INSERT Statements for Data in Book Examples
  • Appendix F. Glossary
  • Appendix G. Bonus Exercises

Workshop

The following workshop is composed of a series of quiz questions and practical exercises. The quiz questions are designed to test your overall understanding of the current material. The practical exercises are intended to afford you the opportunity to apply the concepts discussed during the current hour, as well as build upon the knowledge acquired in previous hours of study. Please take time to complete the quiz questions and exercises before continuing. Refer to Appendix C,"Answers to Quizzes and Exercises," for answers.

Quiz

1. What type of join would you use to return records from one table, regardless of the existence of associated records in the related table?

2. The join conditions are located in what part of the SQL statement?

3. What type of join do you use to evaluate equality among rows of related tables?

4. What happens if you select from two different tables but fail to join the tables?

5. Use the following tables:

   ORDERS_TBL
   ORD_NUM	VARCHAR(10)	NOT NULL	PRIMARY KEY
   CUST_ID	VARCHAR(10)	NOT NULL
   PROD_ID	VARCHAR(10)	NOT NULL
   QTY	Integer(6) NOT NULL
   ORD_DATE	DATETIME

   PRODUCTS_TBL
   PROD_ID	VARCHAR(10)	NOT NULL	PRIMARY KEY
   PROD_DESC	VARCHAR(40)	NOT NULL
   COST	DECIMAL(,2) NOT NULL

6. Is the following syntax correct for using an OUTER JOIN?

   SELECT C.CUST_ID, C.CUST_NAME, O.ORD_NUM 
   FROM CUSTOMER_TBL C, ORDERS_TBL O
   WHERE C.CUST_ID(+) = O.CUST_ID(+)
   

Exercises

1. Invoke MySQL, point to your learnsql database, and type the following code and study the result set (Cartesian product):

   
                  SELECT E.LAST_NAME, E.FIRST_NAME, EP.DATE_HIRE 
   
                  FROM EMPLOYEE_TBL E,
        
                  EMPLOYEE_PAY_TBL EP;
   
               

2. Type the following code to properly join the EMPLOYEE_TBL and EMPLOYEE_PAY_TBL tables:

   
                  SELECT E.LAST_NAME, E.FIRST_NAME, EP.DATE_HIRE 
   
                  FROM EMPLOYEE_TBL E,
        
                  EMPLOYEE_PAY_TBL EP
   
                  WHERE E.EMP_ID = EP.EMP_ID;
   
               

3. Write a SQL statement to return the EMP_ID, LAST_NAME, and FIRST_NAME from the EMPLOYEE_TBL and SALARY and BONUS from the EMPLOYEE_PAY_TBL.

4. What is the average employee salary per city?

5. Try writing a few queries with join operations on your own.

Share This