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“LEARNINGSTARTSWITHVIEWINGTHEWORLDDIFFERENTLY.” Knowledgeflow-Amobilelearningplatformprovidesapps,eBooksandvideotutorials. KnowledgeflowbringsyoualearningeBookofLearningPHPandMySQL.ThiseBook isforallinformationtechnology,computerscienceandwebdevelopmentstudentsand professionalsacrosstheworld. Followuson Facebook Googleplus Twitter Formoreinformationvisitusat Knowledgeflow.in knowledgeflowapps.blogspot.in ThankyouforusingKnowledgefloweBooks LEARNINGPHPANDMYSQL 1.IntroductionofPHP 2.FeaturesofPHP 3.VariablesandArrays 4.Operators 5.Functions 6.IntroductionofSQL 7.OperatorsandConditionsofSQL 8.Queries,Sub-queriesand3VL 9.DataControlandDrawbacks 10.PHPwithMySQL 11.CreateandInsertinMySQLusingPHP 12.UpdateandRetrieveinMySQLusingPHP 13.DeleteinMySQLusingPHP 14.MoreeBooksandApps Disclaimer ThiseBookcontentsisforinformationalandstudypurposesonly.TheKnowledgeflow makesnoclaims,promises,orguaranteesabouttheaccuracy,completeness,oradequacy ofthecontentsofthiseBookandnolegalliabilityorotherresponsibilityisacceptedby Knowledgeflowforanyerrors,omissions,orstatementsonthiseBook. Introduction PHPisoriginallyapersonalizedhomepagei.e.Nowusedasaserversidescripting language.Itisusedandexecutedonserver.Itwasintroducemainlyforwebdesigning purpose.PHPwasactuallycreatedRasmusLerdorfin1994.Atpresentitishypertext preprocessor.Itisusedforserversidewebdevelopment.Itcanbeusedasacommandline scripter.ItcanbeusedasaGUIfortheclient.Ithelpedmanysoftwareframeworksto provideRADi.e.rapidapplicationdevelopment.Itprovidesdynamiccontentstoclient. LogoofPHP HistoryofPHP PHPdevelopmentwasstartedbyRasmusLerdorfin1994. HestartedkeepinghispersonalhomepagetowriteaseriesofCGIi.e.common gatewayinterfaceinC. In1997theparserwasrewrittenbyZeevSuraskiandAndyGutmanswhichleadto theexistenceofbasicPHP. Therehadbeenonlytwostablereleaseswithallsecurityandbugfixes. PHPhasamascotwhichisblueelephantwhichwasdesignedbyVincentPointer. FutureofPHP Theversion5.0and5.5whichwerereleasedarerespectivelysupportedtilldate June2016andAugust2017. Version7.0willbereleasedinmidOctoberof2015andwillbesupportedtill2018. Version7.0isreleasedwiththefeatureofuniformvariablesyntax,bitwiseshift consistencyacrossplatformandreturntypedeclaration. Version7.0willcomplementitsalreadyexistingparametertypedeclaration. Version7.0willalsorectifyallthealreadyexistinglongtimeflawsofPHP. LicensingofPHP PHPisafreesoftwarereleasedfreeofcostsoftware. Itslicensestatesthat-productderivedfromPHPmaynotbecalledPHP,normay PHPnameshouldbeappearedwithoutpriorwrittenpermissionfrom [email protected]. YoumayindicatethatyoursoftwarehadbeenworkingwithPHPbysayingFOO insteadofPHP. ShouldnotstateitasPHPFOOorphpfoo. FeaturesofPHP Theyareasfollows. Serverside-PHPwon’texecutewithinthelocalmachineswebbrowser,insteadit willbeexecutedinthewebserver. Crossplatformed-ThisfeatureallowsthePHPscripttorunandexecutedonany operatingsystemandwebserver. HTMLembeddedlanguage-ThismeansthecommandsandstatementofPHPis alreadyembeddedintheHTMLdocument. WorkingofPHP PHPsupportsmanydatabasesanditisopensourcesoftwarewhichisfreetodownload anduse. UsesofPHP PHPcanbeusedforcreationofdynamicwebsite. Forbuildingtemplatethatwouldmakethesitemaintenanceeasy. Forcreationofgraphicsonthefly. Formaintainingthedifferentiationofthetypeofcontenttobeservedonthebasisof theusersbrowser,IPaddress,dateandtimeandvariousotherdetails. Forconductingasurveyonline. Toconnectdatabaseswiththeweb.Fore.g.oracleandMySQL. Helpsinprovidingalinkofcommunicationwithexternalweb. ItperformsreadandprocessXML. SimplescriptinginPHP <HTML> <HEAD> <TITLE> </HEAD> <BODY> <? //HELLOINPHP PRINT(“HELLO”); ?> </BODY> </HTML> ThePHPstatementisfollow<?PRINT(“HELLO”);?> Thiswoulddisplaythemessage“hello”inthewindowbrowser. ThePHPprintfunctiondisplaysthevaluewiththeparenthesisasoutputinnewwindow. ImportantthingsaboutPHPscriptsPHPiscasesensitive. PHPstatementsarestatedbetween<??>. Italwaysendswithsemi-colon. Commentscanbeaddedusing//inthebeginningoftheline. PHPfileshouldnothave.htmlextension. Fileshouldhave.PHPextension. Ifthefiledon’thave.PHPextensionnorhas.htmlextensionthefilewon’tfound, parsedandexecuted. AdvantageofPHPwithhighsecurityi.e.safemodeTheownershipshouldbesameforthescriptbeingexecutedandfilefromwhichit isreadorwritten. ThedirectoryshouldbeownedbytheownerofthePHPscript. PHPcannotexecuteexternalprogramswhicharenotfromthesystem. Variables Variablesareusedtostorevalueslikestringsnumbersetc.Whenavariableisdeclared,it canbeusedagainandagaininyourscript.SymbolusedtorepresentPHPvariablesis“$ “. Syntax $var_name=value; ThereisnoneedtospecifyinPHPthatthevariableusebelongtowhichdatatype.PHP convertsthevariableintocorrectdatatype.Avariablenamecanalsocontainalpha numericalcharactersbutitshouldnotcontainspace. Example <?php $name=‘Raj’; $yearborn=1977; $currentyear=2015; $age=$currentyear-$yearborn; Print(“$nameis$ageyearsold”) ?> Predefinedvariables TheworkenvironmentthatisbeenusedbyyouisbeenaccessedbythePHPscript.Such variablesarestoredinaspecialhashdatalike$_ENVand$_SERVER.Thesevariables canbeusedonlyonetwoincountatatime. Example <HTML> <HEAD><TITLE>Example2</TITLE></HEAD> <BODY> <? print(“hello>”); print(“youareusing$_SERVER[HTTP_SERVER_AGENT]<br>”); print(“yourinternetaddressis$_SERVER[REMOTE_ADDR]<br>”); ?> </BODY> </HTML> Variablefromexternalsource Htmlforms(GETandPOST) InformationfromtheformwhensubmittedtoPHPisautomaticallymadeavailabletothe particularscript. Example <formaction=“foo.php”method=“post”> Name-<inputtype=“text”name=“username”/><br/> Email-<inputtype=“text”name=“email”/><br/> <inputtype=“submit”name=“submit”value=“submitme!”/> </form> Arrays ArrayisanorderedmapactuallyinPHP.Thistypeofoptimizationissothatitcanhave severaldifferentuses.Arraysvaluecanbearrays,treesandevenmultidimensionalarrays. Example Array( Key=>value, Keya=>value2, Keyb=>value3, …. ) Arraycanalsobemadeusingakey/valuepaircombination.Thesearealsoconsideredas associativearraysandhashes.Aneasywaytocompresshashworkistothinkitasatable. Example Country(Key) City(Value) Cambodia PhnomPenh Lebanon Beirut Cuba Habana Indonesia Jakarta Finland Helsinki Table <?php//createthearray( ‘Cambodia’=>‘PhomPenh’, ‘Lebanon’=>‘Beirut’, ‘Cuba’=>‘Habana’, ‘Indonesia=>’Jakarta’, ‘Finland’=>‘Helsinki’); Print($capital[‘Cambodia’]); ?> Predefinedconstantofarray CASE_LOWER CASE_UPPER SORT_ASC SORT_DESC COUNT_NORMAL COUNT_RECURSIVE EXTR_SKIP EXTR_OVERWRITE EXTR_IF_EXISTS. Operators Arithmeticoperators Example Name Result -$a Negation Oppositeof$a $a+$b Addition Sumof$aand $b $a-$b Subtraction Differenceof$a and$b $a*$b Multiplication Productof$a and$b $a/$b Division Quotientof$a and$b $a%$b Modulus Remainderof$a and$b Thedivisionoperatorwouldreturnfloatvalueunlessthetwooperandsareintegers. Example <?php Echo(5%3).”\n”; Echo(5%-3).”\n”; Echo(-5%3).”\n”; Echo(-5%-3).”\n”; ?> Assignmentoperator TherearetwotypesofassignmentoperatorswhicharecommonlyusedinPHP.Theseare representedas“=”and“=>”. Example <?php $a=($b=4)+5; ?> Bitwiseoperator Itallowsevaluationandmanipulationofaspecificbit. Example Name Result $a&$b And Aresetinboth$aand$b $a|$b Or Aresetineither$aor$b $a^$b Xor Notinboth ~$a Not Aresetin$aarenotset $a ≪ $b Shiftleft Shiftsbitsof$a$btoleft $a ≫ $b Shiftright Shiftbitsof$a$btoright Comparisonoperator Itallowsthecomparisontobedonebytheuse. Example Name Result $a==$b Equal Trueif$a=$b $a===$b identical Trueif$a=$b $a!=$b Notequal Trueif$a≠$b $a<>$b Notequal Trueif$a≠$b $a!==$b Notidentical Trueif$a≠$b $a<$b Lessthan Trueif$astrictlylessthan $b $a>$b Greaterthan Trueif$agreaterthan$b Errorcontroloperator Itisrepresentedby‘@‘.Usingthisitwillignoreanyerrorthatisbeenintendedbythe expression. Example <?php $my_file=@file(‘non_existent_file’) $value=@$cache[$key]; ?> Executionoperator Supportsexecutionoperator:backticks(“).Useofbacktickisidenticaltotheshell_exec (). Example <?php $output=“ls–al”; echo“<pre>$output</pre>; ?> Incrementdecrementoperator Theyarepreandpostincrementdecrementoperatorincstyle. Example Name Effect ++$a Pre-increment Increasesbyone $a++ Post-increment Returns,thenincreases —$a Pre-decrement Decreasesthenreturns $a— Post-decrement Returnsthendecreases Logicaloperator Theuseoftwodifferentvariablesistogetdifferentprecedenceasresult. Example Name Result $aand$b And Trueifbotharetrue $aor$b Or Trueifeitheristrue $axor$b Xor Trueifeitheristrue !$a Not Trueif$aisnottrue $a&&$b And Trueifbotharetrue $a||$b Or Trueifeitheristrue Functions FunctionsaregroupsofPHPstatementsgroupedtogetherthatareorcanbeused overandoveragain. Ithasmorethan1000builtinanduserdefinedfunction. Functiondon’texecuteimmediately. Functionsonlyexecutewhenucallthem. Statementmaycontainmultiplefunctions. User-definedfunction Itcanbedefinedasshownintheexample. Example <?php Functionfoo($arg_1,$arg_2,…….,$args_n) Echo“example.\n”; Return$retval; } ?> Functionargument Throughaargumentlisttheinformationcanbepassedtothefunction.Thisisacomma delimitedlistofexpression. Example <?php Functiontakes_array($input) { Echo“$input[0]+$input[1]=“,$input[0]+$input[1]; } ?> Returningvalues Valuesarereturnedusingtheoptionalreturnstatement.Anytypecanbereturned, includingarraysandobjects. Example <?php Functionsquare($num) { Return$num*$num; } Echosquare(4); ?> Internal(built-in)function Thesearealreadysetinthelibrary.TherealsofunctionthatrequirescertainspecifiedPHP extensioncompiled. Example Tocreateimagefunctionweuseimagecreatetruecolor(). Anonymousfunction Thisfunctionisalsoknownasclosure,thishasnospecificname. Example <?php Echopreg_replace_callback(‘~-([a-z])~’,function($match[1]); },‘hello-world’); ?> SQL SQLstandsforstandardquerylanguagewhichisusedtoaccessdatabases.Italsousedto manipulatedatabaseanditisanANSIstandard. MySQListhewidelyusedopensource Relationaldatabasemanagementsystem.MySQLisgenerallyRDBMSbeingusedfor developingweb-basedsoftwareapplicationsandyoucanaddSQLqueriestotheMySQL databasetoinsert,retrieve,updateordeletedata. LogoofMySQL History Itwasdevelopedin1970atIBMwithDonaldD.ChamberlinandRaymondF. Boyce. ItwasfirstnamedasSEQUEL. ThiswassoldtoUSNAVY,C.I.AandU.S.Governmentagenciesafteritspotential wasrecognized. UsesofSQL Usedtoexecutequeryagainstdatabase. Toretrieveadatafromdatabase. Toinsertrecord. Toupdaterecord. Todeleterecord. Tocreateanewdatabase. Tocreatenewtablesindatabase. Tocreatevariousstorageproceduresindatabase. Tocreatevariouskindofviewsinadatabase. Tocreatepermissionsforthefunctioningofvariousproceduresontablesandviews. HowtouseSQLinwebsite OneoftheRDMSPROGRAM. UseofPHPorASP. UseofSQLforthedatatoberetrieved. UseHTML/CSS. MostimportantSQLcommand Select–Toextractanyneededordesiredrecordordatafromdatabase. Update–Toupdateormodifyanydatainthedatabase. Delete–Todeleteorremoveanydatafromdatabase. Insertinto–Toaddorinsertintodatabase. Createdatabase–Tocreateorstartanewdatabase. Alterdatabase–Tomodifyoreditdatabase. Droptable–Toremoveordeleteatableindatabase. Createsindex–Tocreateanewindex. Dropindex-Toremoveordeleteanindex. SyntaxofSQL SELECT*FROMCustomers; SQLisnotcasesensitive.ThismeansbothselectandSELECThavethesamemeaning. VariouslanguageelementsofSQLlanguages Clauses Expression Predicate Query Statement Insignificantwhitespace LanguageelementsofSQL OperatorsinSQL SQLoperatorsareasfollows. Operator Description Example = Equalto John=‘author’ <> Notequalto Dept<>height > Greaterthan 100>6 < Lessthan 6<100 ≥ Greaterthanorequal Rate≥2.6 ≤ Lessthanorequal Rate≤2.6 BETWEEN Inaninclusiverange RangeBETWEEN10AND 20 LIKE Matchthecharacter NAMELIKE‘WILLY%’ ISORISNOT Comparetonull AGEISORISNOTRAJ IN Equaltooneofthe multiplepossible value IDIN(100,120,134) AS Usedtochangename SelectstudentAS‘section whenviewingthe a’ resultortheparticular value ISNOT DISTINCT FORM Equaltovaluegiven orbotharemissing data LoanISNOTDISTINCT FORM-APPLICABLE Conditions SQLexpressionCase-Itisoneofthesearchingtechniquesoffindingthematchingcase.Itwasusedin SQL-92. Example CASEWHENN>0 THEN‘POSITIVEVALUE’ WHEN<0 THEN‘NEGATIVEVALUE’ ELSE ‘ZERO’ When-Thisconditionisthesourcethroughwhichthedataiscomparedwiththeoutput whichissetissimilartoitscondition.Thattimetheactionwhichhastobetakeisdefined usingwhentheconditionwiththewhenstatementisstated. Example CASEa WHEN1 THEN‘ONEORANGE’ WHEN2 THEN‘TWOORANGES’ ELSE ‘CANNOTCOUNTTHATVALUE’ Then-Thisstatementisusedtoexecuteparticularvalueordisplayparticularvaluewhen theconditioninWHENstatementissatisfied. Example CASEb WHEN3 THEN‘threeORANGE’ WHEN4 THEN‘fourORANGES’ ELSE ‘CANNOTCOUNTTHATVALUE’. Else-Whenthewhenconditionisnotsatisfiedtheprocessleadstoanotheroption,thatis definedaselsestatement. Example WHEN5 THEN‘FIVEORANGES’ ELSE ‘CANNOTCOUNTTHATVALUE’. End-Itisusedtoterminatetheprogramwhichleadsthesystemtostoptheexecution. Example CASEx WHEN1 THEN‘COUNT1’ WHEN2 THEN‘COUNT2’ ELSE‘ERROR’ END Queries QueryisthemostcommonlyusedandoneofthekeyoperationsinSQL. ItisdeclaredusingSELECTstatement. Itprovidesuserwithvariousmethodstodescribeandshowhis/herdesireddata. An‘*‘isusedtoshowthatthequeryshouldreturnallcolumnsoftheparticularthat isqueried. ItisarequestinformationmethodusedintheSQLthereforeitisakeyfactorand mostlythebackboneoftheSQL. MySQLquerywindow VariousclausesandkeywordsusedinSQLareasfollows. FROMclause-Thisshowsfromwhereorwhichtabletoretrievedatafrom. Whereclause-Thisincludesapredicateforcomparisonthishelpsinrestrictingof therowthatisbeenreturnedbythequery. Groupbyclause-Usedtoprojectrowsthatareidenticalorhavecommonvalue. Havingclause-ItisusedinfiltrationofrowwhereitcanbecombinedwithGroup byclause. Orderbyclause-Itsortsorarrangesthedatainaformit’sneededtobearranged. Example SELECTBooktitleASTIM, COUNT(*)ASAuthors FROMBook JOINBook_TIM ONBook.isbn=Book_author.isbn GROUPBYBook.title Output Sub-Queries Thesearenestedqueries.Aquerythatisinanotherqueryandthisisembeddedwithinthe whereclause.Sub-Queriesareusuallyusedtoreturndatawhichwillbefurtherusedinthe mainquery. RulesofSub-queries Ithastobeenclosedwithinparenthesis. ItcanhaveonlyonecolumninSELECTclause. ItisnotallowedtouseODERBYquerywhereasinsteadofthatGROUPBYis used. Itcannothaveimmediateenclosureinasetfunction. Useofsub-queries Itisusedtojoinonetablewithothertablesoperation. Thisalsoprovidesfasterremedies.Thisprovidesahierarchicalexecution. Subquerycanusevaluesfromqueryoutside,thesearecorrelatedsubquery. Sub-Query Example SELECTisbn, Name, Price, FROMBook WHEREprice<(SELECTAVG(PRICE)FROMBook) ORDERBYtitle; 3VL 3VLstandsforthree-valuedlogictoSQL.Thereare3fragmentsof3VLwhichareAND, ORandNOT.Theretableswhicharefollowedin3VL. p PANDq q True False Unknown True True False Unknown False False False False False Unknown Unknown Unknown ANDtable p porq q True False Unknown True True True True False True False Unknown Unknown True Unknown Unknown ORtable q NOTq True False False True Unknown Unknown Nottable NULLisoneofthemostfocusedelementofthe3VLandalsohadbeenvery controversial.Itisjustusedtoindicatethemissingorabsenceofvalueanditdoesnot belongtoanydatadomain. Nullrepresentation ThereforebecauseofitsexistenceissueNULLcannevereverresultineithertrueorfalse sothirdnewlogicalvalueisintroducedthatis“UNKNOWN”. Datacontrols TheDataControlLanguage(DCL)allowsuserstoaccessandmanipulateddata.Itsmain statementsareasfollow. GRANTallowsoneormorethanoneusertoperformanoperationonanobject. REVOKEtoeliminateadefaultgrant. Example GRANTSELECT,UPDATE ONexample TOsome_user,another_user; REVOKESELECT,UPDATE ONexample FROMsome_user,another_user; Itcarriesoutfunctionssuchasconnectinsert,select,update,executeanddelete. Proceduralextensions ThedesigningofSQLisdoneinaformofquerycontainedrelationdatabase.The proceduralextensiondiagramofSQLisshownbelow.Thisallowsprogramming containedinformofroutineswhich.Someelementsknowninproceduralextensionof SQLareasfollows. PolymorphismwiththeparametersinSQLofIN,OUTandINOUTmodes. Variousprocedurescallingstatement. AtomicBEGINandENDcall. LocallydeclaredSQLstatement. Errorsignalingandcursorprocessing. Declareddatatypes. Variousconditionalcontrolandloopingstatement. Proceduralextension Drawbacks Portabilitydolackbetweendatabasesystems. Implementationisnotsupportedwithentirefreedombecauseofthesizeand complexityoftheSQL. Thebehavioroftheimplementationatseveralregionsofdatabaseisconfusing sometimes. Thereislittlecommercialincentivetovendorstoenforceitasaneasiertaskforthe usertobringanychangesindatabasesuppliers. User’sevaluationofdatabasesoftwareavoidsfactorssuchashigherperformances forthestandardpriority. Performanceissue SQLhasalsobeenfoundtohaveaconflictincompatibilitywiththeconsumer’s priordatabase. PHPwithMySQL PHPconnectedtoMySQLfordatamanipulation.Italsoprovidescrossplatform functionality. PHPwithMySQL InawebserveritthereisaPHPinterpreterwhichgetaninputfromthePHPfilespace. Thisinputisnothing PHPcreatesaMySQL.Itcanbecreatedbyusing– MySQLi-MySQLimprovement. PDO-PHPdataobjects. Example MySQLi <?Php $servername=“localhost”; $username=“username”; $password=“password”; //Createconnection $conn=newmysqli($servername,$username,$password); //Checkconnection if($conn->connect_error) { die(“Connectionfailed:”.$conn->connect_error); } //Createdatabase $sql=“CREATEDATABASEmyDB”; if($conn->query($sql)===TRUE) { echo“Databasecreatedsuccessfully”; } else { echo“Errorcreatingdatabase:”.$conn->error; } $conn->close(); ?> PDO <?php $servername=“localhost”; $username=“username”; $password=“password”; try { $conn=newPDO(“mysql:host=$servername;dbname=myDB”,$username,$password); //setthePDOerrormodetoexception $conn->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); $sql=“CREATEDATABASEmyDBPDO”; //useexec()becausenoresultreturned $conn->exec($sql); echo“Databasecreated<br>”; } catch(PDOException$e) { echo$sql.“<br>”.$e->getMessage(); } $conn=null; ?> Syntaxrules QueryhastobequotedinPHP. Numericvaluemustbeavoided. NULLvalueshouldnotbequoted,itshouldbeavoided. Highefficientstatements Preparationstatement-IsanSQLstatementusetocreateandsendatemplatetothe particulardatabase. Executestatement-Isusedtobindalltheretrievedvaluesandtoexecutethem. CreatingMySQLdatabaseusingPHP Adminshouldbeprivilegetocreatedatabase.PHPusesmysql_queryforcreationofthe SQLdatabase.Thishastwoparameterfunctioningwhichistruewhencreationis successfulandfalsewhenafailureoccurs. Syntax Boolmysql_query(sql,connection); Example <?php $dbhost=‘localhost:30306’; $dbuser=’root’; $dbpass=‘password’ $conn=mysql_connection($dbhost,$dbuser,$dbpass); If(!conn) { Die(‘couldnotconnect’.mysql_error()); } Echo‘connectsuccess’; $sql=‘createdatabasetest-tb’; $retreval=mysql_query($sql,$conn); If(!$retval) { Die(‘couldnotcreatedatabase‘.mysql_error()); } Echo“databasetest_dbcreateddatabase\n”; Mysql_close($conn); ?> InsertofdatainMySQLdatabaseusingPHP TheinsertstatementcarriesoutthefunctionusingPHPbyusingquerystatement mysql_queryfortheSQLINSERTstatement. Example <?php $dbhost=‘localhost:3036’; $dbuser=‘root’; $dbpass=‘password’; $conn=mysql_connect($dbhost,$dbuser,$dbpass); If(!$conn) { Die(‘Couldnotconnect’.mysql_error()); } $sql=‘INSERTINTOemployee‘. ‘(emp_name,emp_address,emp_salary,join_date)‘. ‘VALUES(“guest”,“XYZ”,2000,NOW())’; mysql_select_db(‘test_db’); $retval=mysql_query($sql,$conn); If(!$retval) { Die(‘couldnotenterdata:‘.mysql_error()); } Echo“Entereddatasuccessfully\n”; mysql_close($conn); ?> UpdateinMySQLDatabaseusingPHP ForupdatinginMySQLthereisaneedofthecommandtobecarriedoutthatisSQL UPDATEstatementthroughPHPfunctionmysql_query. Example <html> <head> <title>UpdateaRecordinMySQLDatabase</title> </head> <body> <?php if(isset($_POST[‘update’])) { $dbhost=‘localhost:3036’; $dbuser=‘root’; $dbpass=‘password’; $conn=mysql_connect($dbhost,$dbuser,$dbpass); If(!$conn) { die(‘Couldnotconnect:‘.mysql_error()); } $emp_id=$_POST[‘emp_id’]; $emp_salary=$_POST[‘emp_salary’]; $sql=“UPDATEemployee“. “SETemp_salary=$emp_salary“. “WHEREemp_id=$emp_id”; mysql_select_db(‘test_db’); $retval=mysql_query($sql,$conn); if(!$retval) { die(‘Couldnotupdatedata:‘.mysql_error()); } echo“Updateddatasuccessfully\n”; mysql_close($conn); } else { ?> <formmethod=“post”action=”<?php$_PHP_SELF?>”> <tablewidth=“400”border=“0”cellspacing=“1”cellpadding=“2”> <tr> <tdwidth=“100”>EmployeeID</td> <td><inputname=“emp_id”type=“text”id=“emp_id”></td> </tr> <tr> <tdwidth=“100”>EmployeeSalary</td> <td><inputname=“emp_salary”type=“text”id=“emp_salary”></td> </tr> <tr> <tdwidth=“100”></td> <td></td> </tr> <tr> <tdwidth=“100”></td> <td> <inputname=“update”type=“submit”id=“update”value=“Update”> </td> </tr> </table> </form> <?php } ?> </body> </html> TheupdatingperformedusingPHPinMySQLprovidesmoreefficiencyandexception. RetrievalinMySQLDatabaseusingPHP RetrievalinSQListermedasfetchthereforetoperformretrievalinSQLusingPHPa codeisbeeninusewhichisasfollow Syntax Mysql_fetch_arrays() Example <?php $dbhost=‘localhost:3036’; $dbuser=‘root’; $dbpass=‘password’; $conn=mysql_connect($dbhost,$dbuser,$dbpass); if(!$conn) { die(‘Couldnotconnect:‘.mysql_error()); } $sql=‘SELECTemp_id,emp_name,emp_salaryFROMemployee’; mysql_select_db(‘test_db’); $retval=mysql_query($sql,$conn); if(!$retval) { die(‘Couldnotgetdata:‘.mysql_error()); } while($row=mysql_fetch_array($retval,MYSQL_ASSOC)) { echo“EMPID:{$row[‘emp_id’]}<br>“. “EMPNAME:{$row[‘emp_name’]}<br>“. “EMPSALARY:{$row[‘emp_salary’]}<br>“. “––––––––––—<br>”; } echo“Fetcheddatasuccessfully\n”; mysql_close($conn); ?> DeletingofMySQLDatabaseusingPHP Thedatabaseonceisnotneededandtheuserdon’twanttohaveitanymoreorwantto freespacethentheusercanpassastatementthatwouldstatetodeletethedatabase throughthemysql_queryfordeletionofdata.ThetermusedinSQLfordeleteisdrop. Example <?php $dbhost=‘localhost:3036’; $dbuser=‘root’; $dbpass=‘password’; $conn=mysql_connect($dBBhost,$dBBuser,$dBBpass); if(!$conn) { Die(‘couldnotconnect:‘.mysql_error()); } $sql=‘DROPDATABASEtest_d’; $retval=mysql_query($sql,$conn); If(!$retval) { Die(‘Couldnotdeletedatabasedb_test‘mysql_error()); } Echo“Databasedeletedsuccessfully\n”; mysql_close($conn); ?> DeletingofdatafromMySQLusingPHP WhenintendedortheuserwantstodeleteanydatafromtheMySQLdatabaseusingPHP theusercanpassastatementstatingthatthroughmysql_query. Example <html> <head> <title>DeletefromMySQLDatabase</title> </head> <body> <?php if(isset($_POST[‘delete’])) { $dBBhost=‘localhost:3036’; $dBBuser=‘root’; $dBBpass=‘password’; $conn=mysql_connect($dBBhost,$dBBuser,$dBbpass); if(!$conn) { Die(‘couldnotconnect:‘.mysql_error()); } $emp_id=$_POST[‘emp_id’]; $sql=“DELETEemployee“. “WHEREemp_id=$emp_id”; mysql_select_db(‘test_d’); $retval=mysql_query($sql,$conn); if(!$retval) { Die(‘couldnotdeletedata:‘.mysql_error()); } Echo“Deletionsuccessful\n”; mysql_close($conn); } else { ?> <formmethod=“post”action=”<?php$_PHP_SELF?>”> <tablewidth=“400”border=“0”cellspacing=“1”cellpadding=“2”> <tr> <tdwidth=“100”>EmployeeID</td> <td><inputEPRORNAME=“ePROR_NAMED”type=“textT”id=“ePROR_idD”></td> </tr> <tr> <tdwidth=“100”></td> <td></td> </tr> <tr> <tdwidth=“100”></td> <td> <inputEPROR=“delete”type=“submit”id=“delete”value=“Delete”> </td> </tr> </table> </form> <?php } ?> </body> </html> YoucantakebackupoftheSQLdatabaseusingfollowingmethods. UsingcommandofSQLthroughPHP. UsingmysqldumpwiththehelpofPHP. ByusingaphpMyAdminuserinterface. Knowledgeflow:moreeBooksandApps GetmoreGooglePlayBooks GetmoreeBooks GetmoreappsfromGooglePlaystore GetmoreappsfromAmazonappstore
