Sams MySQL certification study guide apr 2004 ISBN 0672326329

database servers and other technologies from MySQL AB.Covering both the basic MySQL Core Certification exam and the advanced MySQL Professional Certification exam, MySQL Certification St

database servers and other technologies from MySQL AB.

Covering both the basic MySQL Core

Certification exam and the advanced MySQL

Professional Certification exam, MySQL

Certification Study Guide is the one authority

to look to when you're preparing for either test The book teaches you all the concepts, principles, and techniques that you'll need to know for the Core and Professional

certification exams, and it includes an array

world examples to help you prepare for test day.

Copyright © 2004 by MySQL AB

All rights reserved No part of this book shall be reproduced,stored in a retrieval system, or transmitted by any means,

electronic, mechanical, photocopying, recording, or otherwise,without written permission from the publisher No patent

liability is assumed with respect to the use of the informationcontained herein Although every precaution has been taken inthe preparation of this book, the publisher and author assume

no responsibility for errors or omissions Nor is any liabilityassumed for damages resulting from the use of the informationcontained herein

as accurate as possible, but no warranty or fitness is implied.The information provided is on an "as is" basis The author(s)and the publisher shall have neither liability nor responsibility toany person or entity with respect to any loss or damages arisingfrom the information contained in this book

Any errata for this book are published at

http://www.mysql.com/certification/studyguides

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Sams Publishing offers excellent discounts on this book whenordered in quantity for bulk purchases or special sales For

MySQL® Press is the exclusive publisher of technology books

and materials that have been authorized by MySQL AB MySQLPress books are written and reviewed by the world's leadingauthorities on MySQL technologies, and are edited, produced,and distributed by the Que/Sams Publishing group of PearsonEducation, the worldwide leader in integrated education andcomputer technology publishing For more information on

www.mysql.com or the following areas of the MySQL Web site:Training information: www.mysql.com/training

Support services: www.mysql.com/support

Consulting services: www.mysql.com/consulting

Paul DuBois is a member of the MySQL documentation team,

a database administrator, and a leader in the Open Source andMySQL communities He contributed to the online

"MySQL FAQ and Tools" Internet site

We would like to thank all of our colleagues at MySQL who havehelped build the certification program over the past 18 months,and without whom this book wouldn't have come into existence

A special thank you to Kaj Arnö, who was the person to

conceive and initiate the MySQL Certification program

The MySQL Reference Manual is the primary source of

information on MySQL It is available online in several formatsand languages from the MySQL AB Web site

(http://www.mysql.com/) It is also available as a printed

bound volume from MySQL Press in English and from MITP inGerman

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and commentator We value your opinion and want to know

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When you write, please be sure to include this book's title andauthor as well as your name and phone or email address I willcarefully review your comments and share them with the authorand editors who worked on the book

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Foreword

About This Book

Conventions Used in This BookOther Related Documents

About the Exams

Interpreting DESCRIBE OutputSample Tables

Summary

Although the MySQL™ Relational Database Management

System (RDBMS) has existed for many years, it's only withinthe last two years that MySQL has gained official recognition inmany enterprise settings The growth has been tremendousinjust a few years, the number of MySQL installations worldwidehas risen from a few hundred thousand to an estimated fourmillion in early 2003

The growth of MySQL in the enterprise, paired with downturn inthe economy at the turn of the century, has created a new

phenomenon: There are more companies than ever looking

specifically for people with MySQL skills At the same time,

many people with MySQL knowledge are out looking for a jobafter the burst of the dot-com bubble, which means that

companies interested in hiring can pick and choose at will

MySQL AB, the company behind the MySQL RDBMS (yes, eventhough the MySQL RDBMS is an open source product, there's athriving company behind it) developed the MySQL CertificationProgram to help companies identify individuals with the skillsetthey need and expect from their employees The certificationprogram also helps individuals by setting them apart from

hobbyists, increasing their prospects for finding challenging newtasks

MySQL AB currently offers certification at two levels:

The Core Certification tests basic MySQL knowledge andusage, knowledge that's sufficient to maintain a basic

MySQL installation and to create application programs thatuse MySQL as a backend database

The Professional Certification goes into more detail

This book meets the demand that was created by the

introduction of the MySQL Certification Program How do youprepare for the exams? Reading this study guide is the best way

to enhance your chances of passing the demanding MySQL Coreand Professional exams

Although the topics covered by each exam (as listed in the

"MySQL Certification Candidate Guide") might seem basic, theexams aren't easy, and they require a combination of study andpractical experience This book will help you understand many

of these topics in-depth Combined with real-world experience,this will help you pass the exams

Another means of gaining skills and knowledge to both help youpass the exams and be successful in the field of MySQL

Frisvold, Peter Gulutzan, Mike Hillyer, Arjen Lentz, Max Mether,Heikki Tuuri, Nils Valentin, and Peter Zaitsev

I am happy the book is now out MySQL AB now has an

excellent answer to the most frequent question we get aboutcertification, namely, "How do I best prepare for it?"

Kaj Arnö, MySQL AB, Vice President, Professional Services

This is a study guide for the MySQL Core and Professional

Certification exams It contains both the "Core Study Guide"and the "Professional Study Guide." It should be seen as a

You might find that the wording of a topic covered in this guidecorresponds exactly to the wording of a question on an exam.However, that is the exception, so rote memorization of the

Some features in MySQL are version specific The current examand this book cover MySQL 4, and you should consider a

release date of such a gamma version

happens on the day of the exam, and what happens once youhave passed the exam

The remainder of this study guide covers each section of theexams, as defined in the "MySQL Certification Candidate

Note that the exercises are not always in the same format asthe exam questions The exam questions are in a format that is

suited for testing your knowledge The exercises are designed

to help you get a better understanding of the contents of this

book, and to help you prove to yourself that you really graspthe topics covered

be entered exactly as shown Thus, in an example such as thefollowing, you would substitute the name of some particulartable for table_name:

SELECT * FROM table_name;

In syntax descriptions, square brackets indicate optional

information For example, the following syntax for the SHOWTABLES statement indicates that you can invoke the statementwith or without a FROM clause that specifies a database name:

In most cases, SQL statements are shown with a trailing

semicolon character (;) The semicolon indicates where the

statement examples However, the semicolon is not part of thestatement itself

mysql> SELECT VERSION();

+ -+

| VERSION() |

+ -+

+ -+

Some commands are intended to be invoked from the commandline, such as from a Unix shell prompt or from a Windows

console window prompt In this guide, these commands areshown preceded by a shell> prompt Some Windows-specificexamples use a prompt that begins with C: The prompt youwill actually see on your own system depends on your

command interpreter and the prompt settings you use (Theprompt is likely to be % or $ for a Unix shell and C:\> for a

Windows console.)

SQL keywords such as SELECT or ORDER BY aren't case sensitive

in MySQL and may be specified in any lettercase when you

issue queries However, for this guide, keywords are written inuppercase letters to help make it clear when they're being used

data The latter term includes UPDATE statements, but also

other statements such as INSERT, REPLACE, and DELETE

Example commands generally omit options for specifying

connection parameters, such as host or user to specify theserver host or your MySQL username It's assumed that you'llsupply such options as necessary The "Core Study Guide"

discusses connection parameter options

comprehensive information on the certifications offered,

upcoming certifications and betas, training offers, and so forth.After you've taken a certification exam, the Web site is also

where you will be able to check the status of your certification

The MySQL Certification Candidate Guide

The "MySQL Certification Candidate Guide" contains the overalldescription of the MySQL Certification program, as well as allthe practical information you will need in order to write an

exam The current version of the "Candidate Guide" as of studyguide publication time is included in an appendix However, the

"Candidate Guide" is subject to revision and certain details

might have changed by the time this book reaches you Youshould make sure that you've read the most current version ofthe "Candidate Guide" before going to an exam The latest

One item found at the end of the "Candidate Guide" that youshould note particularly is the "Non-Disclosure and Logo UsageAgreement" (NDA/LUA) You'll be asked to agree to the

agreement when you go to take the exam At that point, legalagreements will probably be the last thing on your mind, so

reading the agreement before you go will save you some

distraction and also some exam time

The NDA/LUA consists of two main parts The "Non-DisclosureAgreement" defines the information you may pass on to othersabout the exams you have attended (actually, it's mostly about

what you're not allowed to tell) The "Logo Usage Agreement"

defines how you may use the MySQL certification logos afteryou've passed an exam and attained a MySQL Certification title

The Certification Mailing List

As an alternative to frequently checking the Web site for newdevelopments in MySQL certification, you can subscribe to thecertification announcement mailing list This is a low-volume list

to which MySQL AB posts news related to the certification

program The subscription address for the mailing list is

certification-subscribe@lists.mysql.com To subscribe, send anempty message to that address

To take a MySQL certification exam, you must go to a VUE testcenter MySQL AB creates the exams and defines the content,the passing score, and so forth VUE is responsible for

delivering the exams to candidates worldwide

Registering for an Exam

There are three ways to register for an exam:

You can use the VUE Web site, http://www.vue.com/mysql.Note that you must preregister on the Web site to set up anaccount with VUE VUE processes your application and

notifies you when your account is ready This process

usually takes about 24 hours After your account has beenset up, you can register for the exam you want to take

be accommodated at the time you want to take the exam

MySQL AB recommends that you use the VUE Web site for

exam registration and payment, but you're welcome to use any

If you register through the Web or a call center, a receipt will besent to you as soon as the registration process is completed Ifyou register directly at the test center, please ask for your

receipt when you submit payment

Going to the Exam

On the day of your exam, you should ensure that you arrive atthe test center well ahead of the appointed time (at least 15minutes early is recommended) As you register, test centerpersonnel will provide information on how much time you canexpect to spend to complete all steps necessary for testing

The Certification Non-Disclosure and Logo Usage Agreement as

it will be presented at the testing station

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Each MySQL Certification Exam lasts 1 ½ hours In that time,you must answer 70 questions

The questions and answers in any particular exam are drawnfrom a large question pool Each section of the exam will have adifferent number of questions, proportional to the percentagesshown in the "MySQL Certification Candidate Guide."

This study guide organizes topic material into the sections

shown in the "Candidate Guide," but you shouldn't expect theexam to follow the same format While you're taking the exam,questions may occur in any order For example, on the CoreCertification Exam, you might be presented with a question on adata import operation, followed by a question pertaining to theData Definition Language

Learning to Read Questions

question is first to understand what the question is asking The

questions are written in very concise language and are

thoroughly checked for readability But you also need to knowhow to interpret any additional information presented with thequestion

One type of information that's often provided is a display of thestructure of a table Instructions for interpreting this

information are given later in this introduction (see the section

"Interpreting DESCRIBE Output")

Answering Questions

You should attempt to answer all exam questions, because anunanswered question counts as an incorrect answer When

taking the exam, you'll be able to move back and forth betweenquestions This makes it possible to initially skip questions

you're unsure of and return to them as time permits You'll also

be able to mark a question "for review," if you want to spendmore time on it later When you've gone through all questions,

a review screen will be presented that contains any questionsthat you've marked for review, as well as all unanswered

or by pressing the corresponding letter on the keyboard

For a multiple-choice/single-answer question, only one response

is correct and you must identify the correct answer from amongthe possible responses Some of the responses provided might

be partially correct, but only one will be completely correct In asingle-answer question, the fields that you can select are circles("radio buttons") and the text in the status bar below the

question says "select the best possible answer."

For a multiple-choice/multiple-answer question, you must

choose all correct answers to get credit for your response As

with single-answer questions, there might be subtle differencesbetween correct and incorrect answers; take your time to readeach possible answer carefully before deciding whether it is

correct In multiple-answer questions, the fields that you canselect are square ("check boxes") and the status line says

"Select between 1 and n answers," where n is the total number

of possible answers

For a question requiring a textual answer, you must respond byfilling in a text box with one or more words in the text box

provided You must spell each word correctly However, you

need not worry about lettercase or spacing Uppercase and

lowercase are considered the same, and multiple whitespacecharacters are considered to be equivalent to a single spacecharacter

A multiple-choice/single-answer question Note that each

answer key has a circle ("radio button") beside it, and the

status bar says "select the best response."

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possible answers; however, you should always follow the

onscreen instructions If the instructions tell you to use onlyone word, use only one word Otherwise, you're certain to

receive no credit for your response

After the Exam

Unless you're taking part in a Beta exam, you'll receive yourgrade as soon as you complete the exam The test center willprovide you with a score report

If you pass, MySQL AB will mail your certificate shortly afterreceiving your exam results from the test center

If you get a failing grade on the exam, you have the option ofretaking it Although MySQL AB does not place restrictions onhow soon you can retake an exam, doing so is not advised untilyou've done some further study

Whether you pass or fail, after you've taken any MySQL

certification exam, you'll receive a letter from MySQL AB tellingyou how to gain access to extra information at

http://www.mysql.com Two main entry points into this area are

The candidate area:

http://www.mysql.com/certification/candidate

Here, you will find information specially set aside for MySQLcertification candidates For example, there might be specialoffers, information on prereleases of new certifications, and

so on

The results area:

http://www.mysql.com/certification/results

Warning

For every popular certification exam, there are always

enterprising individuals who set up so-called "braindump"

Internet sites, where people anonymously post questions andanswers purported to be from the exam Please note these

cautions about using or contributing to these sites:

If you use such a site, you might be misled The answers

they provide are often wrong Most of the questions have

never been in an exam; they exist only in the submitter'shead As a result, instead of being helpful, such sites lead toconfusion

If you contribute to such a site by posting your own examquestions and answers, you risk forfeiting not only the

certification for the exam about which you have posted

details, but your involvement in the entire MySQL

Certification program You might thus never be able to

regain MySQL certification credentials

the mysql program For example, assume that a question

requires you to know about a table named City The table's

The Type value shows the column datatype

The Null indicator is the word YES if the column can contain

If the Key value is the keyword MUL, this indicates thatthe column is the first column of a nonunique index or aunique-valued index that can contain NULL values

It's possible that more than one of the Key values may

apply to a given column of a table For example, a columnthat is a PRIMARY KEY might also be part of other indexes.When it's possible for more than one of the Key values todescribe an index, DESCRIBE displays the one with the

highest priority, in the order PRI, UNI, MUL

Because a column can be part of several indexes, the Key

values do not necessarily provide an exhaustive description

of a table's indexes However, for purposes of the exam,you should assume that the table descriptions given provideall the information needed to correctly answer the question

Default shows the column's default value This is the valuethat MySQL assigns to the column when a statement thatcreates a new record does not provide an explicit value forthe column (For example, this can happen with the INSERT,

REPLACE, and LOAD DATA INFILE statements.)

The Extra value displays other details about the column.The only Extra detail about which you need be concernedfor the exam is the value auto_increment This value

indicates that the column has the AUTO_INCREMENT

attribute (The ID column shown in the example is such aninstance.)

You can read more about indexing, column datatypes, default