6 Task 3 Obtaining Back-end DataPHP动态网站开发项目教程课件

Project1MemberManagementSystemSchoolofSoftware,ChengduPolytechnicLecturer:MuQichunTask3ObtainingBack-endDataFormSettingClicktheSubmitbuttonontheregistrationpage,thesystemwillautomaticallyredirecttotheback-endpageappointedbyaction.Ontheback-endpage,usetheglobalarray$_GETor$_POSTtoobtainthedatasubmittedbyafront-endform.Themethodforobtainingdataisdeterminedbythedatasubmissionmethodusedbythefront-endform.Ifthefrontendusesthegetmethodtosubmitthedata,apply$_GET.Ifthefrontendusesthepostmethodtosubmitthedata,apply$_POST.Ofcourse,theglobalarray$_REQUESTcanbeusedforreadingthedatasubmittedbythefront-endform,whichcanbereadwithgetandpostboth.Toobtainthevaluecompletedbythefront-endforminthebackend,somesettingsmustbemadetotheformfield.Addoneattributenametoeachformfield.Addthesameattributenametotheradiobuttons(orcheckboxes)ofthesamegroup.Addoneattributevaluetotheradiobuttonsandthecheckbox.Forthecheckbox,settheattributenameintheformofonedata.ClicktheSubmitbuttonintheform,thesystemwillredirecttothepageappointedbytheattributeactionofthetagform,andcarrycorrespondingfront-enddata.Therearetwocarryingmethods,namelygetandpost,whichcanbesetthroughtheattributemethodofthetagform.Differencesbetweengetandpostinclude:Getisunsafe,becausethedataisplacedinarequestedURLinthetransmissionprocess.However,alloperationsofPostareinvisibletotheuser.Gettransmitsasmallamountofdata,mainlyduetotherestrictiononURLlength,whilePosttransmitsalargeamountofdata,withnorestrictionsmadebydefaultingeneralcase.ThevaluesofdatasetsinFormrestrictedbyGetmustbeASCIIcharacters,whilePostsupporttheentireISO10646characterset.However,theexecutionefficiencyofGetishigherthanthatofPost.Getisthedefaultmethodforsubmittingaform.ObtainingFormDatawithPHPClicktheSubmitbuttonontheregistrationpage,thesystemwillautomaticallyredirecttotheback-endpageappointedbyaction.Ontheback-endpage,usetheglobalarray$_GETor$_POSTtoobtainthedatasubmittedbyafront-endform.Themethodforobtainingdataisdeterminedbythedatasubmissionmethodusedbythefront-endform.Ifthefrontendusesthegetmethodtosubmitthedata,apply$_GET.Ifthefrontendusesthepostmethodtosubmitthedata,apply$_POST.Ofcourse,theglobalarray$_REQUESTcanbeusedforreadingthedatasubmittedbythefront-endform,whichcanbereadwithgetandpostboth.CreatethepostReg.phpfileinaproject,andenterthefollowingcodestoreadandtestback-enddata.ObtainingFormDatawithPHPRunthesingup.phpfile,entereachdataintheform,clicktheSubmitbutton,entertheback-endpage,andviewtheoperatingresults.ObtainingFormDatawithPHPApredefinedvariable$_POSTisusedforcollectingvaluesinformsfrommethod="post"inPHP,andisofthearraytype.MessagessentfromaformwiththePOSTmethodareinvisibletoallpersons(notdisplayedintheaddressbarofthebrowser),withoutanyrestrictiononitsvolume.However,bydefault,themaximuminformationsentbythePOSTmethodis8MB(whichcanbesetpost_max_sizeinthephp.inifile).Doyourememberhowtosettheattributenameinafront-endformforeachcontrol.Use$_POST['username']toreadthevalueofacontrolwiththenameofusernameofthefrom-endformfromaback-endfile.Asmultiplevaluescanbeselectedinthecheckbox,thenameintheformofthefunctionformfav[]isusedinafront-endform.Certainly,onearrayisreadattheendwith$_POST['fav'].UsethefunctionechotooutputthevalueofonevariableinPHP.However,asdirectoutputisnotavailableforarrays,thefunctionimplodeisusedforprocessing.Thefunctionimplode()returnsacharacterstringcomposedofarrayelements,andthefirstparameterstipulatesthecontentplacedbetweenarrayelements,withthedefaultvalueof""(nullcharacterstring).Here,acommaisusedforconnectingthearrayelements.Thesecondparameteristhespecificarraytobeprocessed.ObtainingFormDatawithPHPInthesexcontrolinafront-endform,thevalue1issetfortheoption“Male”,whilethevalue0issetfortheoption“Female”.Therefore,thevaluesofsexreadintheback-endfileare1and0.However,thevaluesarewrongif1and0aredirectlyoutputted,whichneedtoberespectivelyconvertedto“Male”and“Female”.Usetheexpression?heretofinishtheoperation.Theexpression?equatestothedoublebranchstatementif...esle.Iftheexpressionaheadof?istrue,returnthevaluebehind?.Otherwise,returnthevaluesbehind:.Judgewhether$sexequalsto1.Ifyes,output“Male”.Ifno,output“Female”.Directlyplaceacharacterstringinapairofquotationmarksorsinglequotationmarksinthefunctionecho,tooutputthecharacterstringasis.Directlyplacethevariablesbetweendoublequotationmarkstooutputthem.However,ifonevariableisdirectlyinsertedbetweensinglequotationmarks,thevariablescannotbeparsed,withthenameofthevariableitselfdirectlydisplayedinthebrowser.Insuchcase,connectorsareused,forexample