Sams teach yourself SQL in 10 minutes 3rd edition apr 2004 ISBN 0672325675

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TableofContents
Index

SamsTeachYourselfSQLin10Minutes,
ThirdEdition
ByBenForta

Publisher :SamsPublishing
PubDate :March31,2004
ISBN :0-672-32567-5
Pages :256
Slots :0.5


SamsTeachYourselfSQLin10Minuteshas
establisheditselfasthegoldstandardfor
introductorySQLbooks,offeringafast-paced
accessibletutorialtothemajorthemesand
techniquesinvolvedinapplyingtheSQL
language.Forta'sexamplesareclearandhis
writingstyleiscrispandconcise.Aswith
earliereditions,thisrevisionincludes
coverageofcurrentversionsofallmajor
commercialSQLplatforms.Newthistime
aroundiscoverageofMySQL,and

PostgreSQL.Allexampleshavebeentested
againsteachSQLplatform,with
incompatibilitiesorplatformdistinctives
calledoutandexplained.



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•


TableofContents
Index

SamsTeachYourselfSQLin10Minutes,
ThirdEdition
ByBenForta

Publisher :SamsPublishing
PubDate :March31,2004
ISBN :0-672-32567-5
Pages :256
Slots :0.5

Copyright
AbouttheAuthor
Acknowledgments
WeWanttoHearfromYou!
Introduction
WhoistheTeachYourselfSQLBookFor?
DBMSsCoveredinThisBook
ConventionsUsedinThisBook


Chapter1.UnderstandingSQL
DatabaseBasics

WhatIsSQL?




TryItYourself
Summary


Chapter2.RetrievingData
TheSELECTStatement

RetrievingIndividualColumns




RetrievingMultipleColumns
RetrievingAllColumns




Summary


Chapter3.SortingRetrievedData
SortingData

SortingbyMultipleColumns




SortingbyColumnPosition



Summary

SpecifyingSortDirection

Chapter4.FilteringData
UsingtheWHEREClause

TheWHEREClauseOperators



Summary


Chapter5.AdvancedDataFiltering
CombiningWHEREClauses

UsingtheINOperator




UsingtheNOTOperator
Summary


Chapter6.UsingWildcardFiltering
UsingtheLIKEOperator

TipsforUsingWildcards

Summary


Chapter7.CreatingCalculatedFields
UnderstandingCalculatedFields

ConcatenatingFields




PerformingMathematicalCalculations
Summary


Chapter8.UsingDataManipulationFunctions
UnderstandingFunctions

UsingFunctions



Summary


Chapter9.SummarizingData
UsingAggregateFunctions

AggregatesonDistinctValues

CombiningAggregateFunctions
Summary


Chapter10.GroupingData
UnderstandingDataGrouping

CreatingGroups




FilteringGroups
GroupingandSorting






SELECTClauseOrdering
Summary


Chapter11.WorkingwithSubqueries
UnderstandingSubqueries

FilteringbySubquery




UsingSubqueriesAsCalculatedFields
Summary


Chapter12.JoiningTables
UnderstandingJoins

CreatingaJoin



Summary


Chapter13.CreatingAdvancedJoins
UsingTableAliases

UsingDifferentJoinTypes




UsingJoinswithAggregateFunctions

Summary

UsingJoinsandJoinConditions


Chapter14.CombiningQueries
UnderstandingCombinedQueries

CreatingCombinedQueries



Summary


Chapter15.InsertingData
UnderstandingDataInsertion

CopyingfromOneTabletoAnother



Summary


Chapter16.UpdatingandDeletingData
UpdatingData

DeletingData

GuidelinesforUpdatingandDeletingData
Summary


Chapter17.CreatingandManipulatingTables
CreatingTables

UpdatingTables




DeletingTables



Summary



RenamingTables

Chapter18.UsingViews

UnderstandingViews




CreatingViews
Summary


Chapter19.WorkingwithStoredProcedures
UnderstandingStoredProcedures

WhytoUseStoredProcedures




ExecutingStoredProcedures



Summary

CreatingStoredProcedures


Chapter20.ManagingTransactionProcessing
UnderstandingTransactionProcessing

ControllingTransactions



Summary


Chapter21.UsingCursors
UnderstandingCursors

WorkingwithCursors



Summary


Chapter22.UnderstandingAdvancedSQLFeatures
UnderstandingConstraints

UnderstandingIndexes




UnderstandingTriggers



Summary

DatabaseSecurity


AppendixA.SampleTableScripts
UnderstandingtheSampleTables

ObtainingtheSampleTables


AppendixB.WorkinginPopularApplications
UsingAquaDataStudio

UsingDB2




UsingMacromediaColdFusion




UsingMicrosoftASP




UsingMicrosoftQuery

UsingMySQL



UsingPHP

UsingMicrosoftAccess
UsingMicrosoftASP.NET
UsingMicrosoftSQLServer
UsingOracle
UsingPostgreSQL






UsingQueryTool



ConfiguringODBCDataSources

UsingSybase


AppendixC.SQLStatementSyntax

ALTERTABLE

COMMIT




CREATEINDEX




CREATETABLE




DELETE




INSERT




ROLLBACK

UPDATE

CREATEPROCEDURE
CREATEVIEW
DROP
INSERTSELECT
SELECT


AppendixD.UsingSQLDatatypes
StringDatatypes

NumericDatatypes






DateandTimeDatatypes
BinaryDatatypes
AppendixE.SQLReservedWords
Index


Copyright
Copyright©2004bySamsPublishing
Allrightsreserved.Nopartofthisbookshallbereproduced,
storedinaretrievalsystem,ortransmittedbyanymeans,

electronic,mechanical,photocopying,recording,orotherwise,
withoutwrittenpermissionfromthepublisher.Nopatent
liabilityisassumedwithrespecttotheuseoftheinformation
containedherein.Althougheveryprecautionhasbeentakenin
thepreparationofthisbook,thepublisherandauthorassume
noresponsibilityforerrorsoromissions.Norisanyliability
assumedfordamagesresultingfromtheuseoftheinformation
containedherein.
LibraryofCongressCatalogCardNumber:2003093137
PrintedintheUnitedStatesofAmerica
FirstPrinting:April2004
070605044321

Trademarks
Alltermsmentionedinthisbookthatareknowntobe
trademarksorservicemarkshavebeenappropriately
capitalized.SamsPublishingcannotattesttotheaccuracyof
thisinformation.Useofaterminthisbookshouldnotbe
regardedasaffectingthevalidityofanytrademarkorservice
mark.

WarningandDisclaimer


Everyefforthasbeenmadetomakethisbookascompleteand
asaccurateaspossible,butnowarrantyorfitnessisimplied.
Theinformationprovidedisonan"asis"basis.Theauthorand
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fromtheinformationcontainedinthisbook.

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Credits
AssociatePublisher
MichaelStephens
DevelopmentEditor
MarkRenfrow
ManagingEditor
CharlotteClapp
ProjectEditor


DanKnott
Indexer
TomDinse
Proofreader
LeslieJoseph
TechnicalEditor
ChristopherMcGee
PublishingCoordinator
CindyTeeters

InteriorDesigner
GaryAdair
CoverDesigner
GaryAdair


AbouttheAuthor
BenFortaisMacromedia'sSeniorTechnicalEvangelistandhas
almost20yearsofexperienceinthecomputerindustryin
productdevelopment,support,training,andproductmarketing.
Benistheauthorofthebest-sellingColdFusionWebApplication
ConstructionKitandAdvancedColdFusionDevelopment(both
publishedbyQue),SamsTeachYourselfRegularExpressionsin
10Minutes(inthissameseries),andalsobooksonFlash,Java,
WAP,Windows2000,andothersubjects.Hehasextensive
experienceindatabasedesignanddevelopment,has
implementeddatabasesforseveralhighlysuccessful
commercialsoftwareprograms,andisafrequentlecturerand
columnistonInternetanddatabasetechnologies.Bornin
London,England,andeducatedinLondon,NewYork,andLos
Angeles,BennowlivesinOakPark,Michigan,withhiswife
Marcyandtheirsevenchildren.Benwelcomesyouremailat
,andinvitesyoutovisithisWebsiteat
.


Acknowledgments
ThankstotheteamatSamsforalltheseyearsofsupport,
dedication,andencouragement.AspecialthankyoutoMike
StephensandMarkRenfrowforshepherdingthisnewedition

fromconcepttoreality(aprocessthatrequiredthemto
occasionallyshepherdme,too).
Thankstothemanyhundredsofyouwhoprovidedfeedbackon
thefirsttwoeditionsofthisbook.Fortunately,mostofitwas
positive,andallofitwasappreciated.Theenhancementsand
changesinthiseditionareadirectresponsetoyourfeedback.
Andfinally,thankstothemanythousandsofyouwhobought
thepreviouseditionsofthisbook(inEnglish,andinanyofthe
manytranslations),makingitnotjustmybest-sellingtitle,but
alsooneofthebest-sellingbooksonthesubject.Your
continuedsupportisthehighestcomplimentanauthorcanever
bepaid.


WeWanttoHearfromYou!
Asthereaderofthisbook,youareourmostimportantcritic
andcommentator.Wevalueyouropinionandwanttoknow
whatwe'redoingright,whatwecoulddobetter,whatareas
you'dliketoseeuspublishin,andanyotherwordsofwisdom
you'rewillingtopassourway.
AsanassociatepublisherforSamsPublishing,Iwelcomeyour
comments.Youcanemailorwritemedirectlytoletmeknow
whatyoudidordidn'tlikeaboutthisbookaswellaswhatwe
candotomakeourbooksbetter.
PleasenotethatIcannothelpyouwithtechnicalproblems
relatedtothetopicofthisbook.WedohaveaUserServices
group,however,whereIwillforwardspecifictechnical
questionsrelatedtothebook.
Whenyouwrite,pleasebesuretoincludethisbook'stitleand
authoraswellasyourname,emailaddress,andphonenumber.

Iwillcarefullyreviewyourcommentsandsharethemwiththe
authorandeditorswhoworkedonthebook.

Email:



Mail:

MichaelStephens
AssociatePublisher
SamsPublishing
800East96thStreet
Indianapolis,IN46240USA

FormoreinformationaboutthisbookoranotherSams
Publishingtitle,visitourWebsiteatwww.samspublishing.com.
TypetheISBN(0672325675)orthetitleofthisbookinthe
Searchfieldtofindthepageyou'relookingfor.


Introduction
SQListhemostwidelyuseddatabaselanguage.Whetheryou
areanapplicationdeveloper,databaseadministrator,Web
applicationdesigner,orMicrosoftOfficeuser,agoodworking
knowledgeofSQLisanimportantpartofinteractingwith
databases.
Thisbookwasbornoutofnecessity.IhadbeenteachingWeb
applicationdevelopmentforseveralyears,andstudentswere
constantlyaskingforSQLbookrecommendations.Thereare

lotsofSQLbooksoutthere.Someareactuallyverygood.But
theyallhaveonethingincommon:formostuserstheyteach
justtoomuchinformation.InsteadofteachingSQLitselfmost
booksteacheverythingfromdatabasedesignandnormalization
torelationaldatabasetheoryandadministrativeconcerns.And
whilethoseareallimportanttopics,theyarenotofinterestto
mostofuswhojustneedtolearnSQL.
Andso,notfindingasinglebookthatIfeltcomfortable
recommending,Iturnedthatclassroomexperienceintothe
bookyouareholding.SamsTeachYourselfSQLin10Minutes
willteachyouSQLyouneedtoknow,startingwithsimpledata
retrievalandworkingontomorecomplextopicsincludingthe
useofjoins,subqueries,storedprocedures,cursors,triggers,
andtableconstraints.You'lllearnmethodically,systematically,
andsimplyinlessonsthatwilleachtake10minutesorlessto
complete.
Nowinitsthirdedition,thisbookhastaughtSQLtohundreds
ofthousandsofusers,andnowitisyourturn.Soturnto
Lesson1,andgettowork.You'llbewritingworldclassSQLin
notimeatall.


WhoistheTeachYourselfSQLBookFor?
Thisbookisforyouif
YouarenewtoSQL.
YouwanttoquicklylearnhowtogetthemostoutofSQL.
YouwanttolearnhowtouseSQLinyourownapplication
development.
YouwanttobeproductivequicklyandeasilyinSQLwithout
havingtocallsomeoneforhelp.

DBMSsCoveredinThisBook
Forthemostpart,theSQLtaughtinthisbookwillapplytoany
DatabaseManagementSystem(DBMS).However,asallSQL
implementationsarenotcreatedequal,thefollowingDBMSsare
explicitlycovered(andspecificinstructionsornotesare
includedwhereneeded):
IBMDB2
MicrosoftAccess
MicrosoftSQLServer
MySQL
Oracle
PostgreSQL
SybaseAdaptiveServer
ExampledatabasesandSQLscriptsarealsoavailableforallof
theseDBMSs.


ConventionsUsedinThisBook
Thisbookusesdifferenttypefacestodifferentiatebetweencode
andregularEnglish,andalsotohelpyouidentifyimportant
concepts.
Textthatyoutypeandtextthatshouldappearonyourscreen
ispresentedinmonospacetype.

Itwilllooklikethistomimicthewaytextlooksonyourscre
Placeholdersforvariablesandexpressionsappearinmonospace
italicfont.Youshouldreplacetheplaceholderwiththe
specificvalueitrepresents.

Thisarrow( )atthebeginningofalineofcodemeansthata
singlelineofcodeistoolongtofitontheprintedpage.
Continuetypingallthecharactersafterthe asthoughthey
werepartoftheprecedingline.
ANotepresentsinterestingpiecesofinformationrelatedtothe
surroundingdiscussion.

ATipoffersadviceorteachesaneasierwaytodosomething.


ACautionadvisesyouaboutpotentialproblemsandhelpsyousteer
clearofdisaster.

NewTermiconsprovidecleardefinitionsofnew,essentialterms.

TheInputiconidentifiescodethatyoucantypein
yourself.

TheOutputiconhighlightstheoutputproducedby
runningaprogram.

TheAnalysisiconalertsyoutotheauthor'slineby-lineanalysisofaprogram.


Lesson1.UnderstandingSQL
Inthislesson,you'lllearnexactlywhatSQLisandwhatitwill
doforyou.


DatabaseBasics

ThefactthatyouarereadingabookonSQLindicatesthatyou,
somehow,needtointeractwithdatabases.SQLisalanguage
usedtodojustthis,sobeforelookingatSQLitself,itis
importantthatyouunderstandsomebasicconceptsabout
databasesanddatabasetechnologies.
Whetheryouareawareofitornot,youusedatabasesallthe
time.Eachtimeyouselectanamefromyouremailaddress
book,youareusingadatabase.Ifyouconductasearchonan
Internetsearchsite,youareusingadatabase.Whenyoulog
intoyournetworkatwork,youarevalidatingyournameand
passwordagainstadatabase.EvenwhenyouuseyourATM
cardatacashmachine,youareusingdatabasesforPIN
numberverificationandbalancechecking.
Buteventhoughweallusedatabasesallthetime,there
remainsmuchconfusionoverwhatexactlyadatabaseis.Thisis
especiallytruebecausedifferentpeopleusethesamedatabase
termstomeandifferentthings.Therefore,agoodplacetostart
ourstudyiswithalistandexplanationofthemostimportant
databaseterms.
ReviewingBasicConceptsWhatfollowsisaverybriefoverviewof
somebasicdatabaseconcepts.Itisintendedtoeitherjoltyourmemory
ifyoualreadyhavesomedatabaseexperience,ortoprovideyouwith
theabsolutebasics,ifyouarenewtodatabases.Understanding
databasesisanimportantpartofmasteringSQL,andyoumightwantto
findagoodbookondatabasefundamentalstobrushuponthesubjectif
needed.


WhatIsaDatabase?
Thetermdatabaseisusedinmanydifferentways,butforour

purposes(andindeed,fromSQL'sperspective)adatabaseisa
collectionofdatastoredinsomeorganizedfashion.The
simplestwaytothinkofitistoimagineadatabaseasafiling
cabinet.Thefilingcabinetissimplyaphysicallocationtostore
data,regardlessofwhatthatdataisorhowitisorganized.
DatabaseAcontainer(usuallyafileorsetoffiles)tostoreorganized
data.

MisuseCausesConfusionPeopleoftenusethetermdatabasetorefer
tothedatabasesoftwaretheyarerunning.Thisisincorrect,anditisa
sourceofmuchconfusion.Databasesoftwareisactuallycalledthe
DatabaseManagementSystem(orDBMS).Thedatabaseisthe
containercreatedandmanipulatedviatheDBMS.Adatabasemightbea
filestoredonaharddrive,butitmightnot.Andforthemostpartthisis
notevensignificantasyouneveraccessadatabasedirectlyanyway;
youalwaysusetheDBMSanditaccessesthedatabaseforyou.

Tables
Whenyoustoreinformationinyourfilingcabinetyoudon'tjust
tossitinadrawer.Rather,youcreatefileswithinthefiling
cabinet,andthenyoufilerelateddatainspecificfiles.


Inthedatabaseworld,thatfileiscalledatable.Atableisa
structuredfilethatcanstoredataofaspecifictype.Atable
mightcontainalistofcustomers,aproductcatalog,orany
otherlistofinformation.
TableAstructuredlistofdataofaspecifictype.

Thekeyhereisthatthedatastoredinthetableisonetypeof

dataoronelist.Youwouldneverstorealistofcustomersanda
listofordersinthesamedatabasetable.Doingsowouldmake
subsequentretrievalandaccessdifficult.Rather,you'dcreate
twotables,oneforeachlist.
Everytableinadatabasehasanamethatidentifiesit.That
nameisalwaysuniquemeaningnoothertableinthatdatabase
canhavethesamename.
TableNamesWhatmakesatablenameuniqueisactuallya
combinationofseveralthingsincludingthedatabasenameandtable
name.Somedatabasesalsousethenameofthedatabaseowneras
partoftheuniquename.Thismeansthatwhileyoucannotusethe
sametablenametwiceinthesamedatabase,youdefinitelycanreuse
tablenamesindifferentdatabases.

Tableshavecharacteristicsandpropertiesthatdefinehowdata
isstoredinthem.Theseincludeinformationaboutwhatdata
maybestored,howitisbrokenup,howindividualpiecesof
informationarenamed,andmuchmore.Thissetofinformation
thatdescribesatableisknownasaschema,andschemaare


usedtodescribespecifictableswithinadatabase,aswellas
entiredatabases(andtherelationshipbetweentablesinthem,
ifany).
SchemaInformationaboutdatabaseandtablelayoutandproperties.

ColumnsandDatatypes
Tablesaremadeupofcolumns.Acolumncontainsaparticular
pieceofinformationwithinatable.
ColumnAsinglefieldinatable.Alltablesaremadeupofoneormore

columns.

Thebestwaytounderstandthisistoenvisiondatabasetables
asgrids,somewhatlikespreadsheets.Eachcolumninthegrid
containsaparticularpieceofinformation.Inacustomertable,
forexample,onecolumncontainsthecustomernumber,
anothercontainsthecustomername,andtheaddress,city,
state,andzipareallstoredintheirowncolumns.
BreakingUpDataItisextremelyimportanttobreakdataintomultiple
columnscorrectly.Forexample,city,state,andzipshouldalwaysbe
separatecolumns.Bybreakingtheseout,itbecomespossibletosortor
filterdatabyspecificcolumns(forexample,tofindallcustomersina
particularstateorinaparticularcity).Ifcityandstatearecombined
intoonecolumn,itwouldbeextremelydifficulttosortorfilterbystate.


Eachcolumninadatabasehasanassociateddatatype.A
datatypedefineswhattypeofdatathecolumncancontain.For
example,ifthecolumnistocontainanumber(perhapsthe
numberofitemsinanorder),thedatatypewouldbeanumeric
datatype.Ifthecolumnweretocontaindates,text,notes,
currencyamounts,andsoon,theappropriatedatatypewould
beusedtospecifythis.
DatatypeAtypeofalloweddata.Everytablecolumnhasanassociated
datatypethatrestricts(orallows)specificdatainthatcolumn.

Datatypesrestrictthetypeofdatathatcanbestoredina
column(forexample,preventingtheentryofalphabetical
charactersintoanumericfield).Datatypesalsohelpsortdata
correctly,andplayanimportantroleinoptimizingdiskusage.

Assuch,specialattentionmustbegiventopickingtheright
datatypewhentablesarecreated.
DatatypeCompatibilityDatatypesandtheirnamesareoneofthe
primarysourcesofSQLincompatibility.Whilemostbasicdatatypesare
supportedconsistently,manymoreadvanceddatatypesarenot.And
worse,occasionallyyou'llfindthatthesamedatatypeisreferredtoby
differentnamesindifferentDBMSs.Thereisnotmuchyoucandoabout
this,butitisimportanttokeepinmindwhenyoucreatetableschemas.


Rows
Datainatableisstoredinrows;eachrecordsavedisstoredin
itsownrow.Again,envisioningatableasaspreadsheetstyle
grid,theverticalcolumnsinthegridarethetablecolumns,and
thehorizontalrowsarethetablerows.
Forexample,acustomerstablemightstoreonecustomerper
row.Thenumberofrowsinthetableisthenumberofrecords
init.
RowArecordinatable.

RecordsorRows?Youmayhearusersrefertodatabaserecordswhen
referringtorows.Forthemostpart,thetwotermsareused
interchangeably,butrowistechnicallythecorrectterm.

PrimaryKeys
Everyrowinatableshouldhavesomecolumn(orsetof
columns)thatuniquelyidentifiesit.Atablecontaining
customersmightuseacustomernumbercolumnforthis
purpose,whereasatablecontainingordersmightusetheorder
ID.AnemployeelisttablemightuseanemployeeIDorthe

employeesocialsecuritynumbercolumn.