33 Task 8 One Person Can Only Cast 5 Votes for One Vehicle A DayPHP動態(tài)網(wǎng)站開發(fā)項目教程課件

Project2OnlineVotingSystemSchoolofSoftware,ChengduPolytechnicLecturer:MuQichunTask8OnePersonCanOnlyCast5VotesforOneVehicleA

DayProgrammingVotingrestrictions

are

the

functionfoundinmostonlinevotingsystems.Basedondifferentneeds,therewillbedifferentrestrictions.Thebasicroleofvotingrestrictionsistoavoidfactitiously

ballotrigging.Theregularmeansareasfollows:IPrestrictions:Itisthemostcommonanti-ballotriggingmethod,whichcanlimiteachIPtovoteonlyonceduringacertainperiodoftime.BecauseIPwithhighreliability

isdifficulttoforge.It

isrecommendedtoopenit.Makesurethat,ifitisunderthesamelocalareanetwork(forexample,usingthesamerouter'swifi),theremaybesituationswheredifferentterminalshavethesameIP.Anditwillnothappenifweareusingamobilephonecarriernetwork.Devicerestrictions:Thevotingplatformmarksdevicesthathavealready

voted(computers,mobilephones,etc.)

using

technologiessuchasCookie.Thismethodisnotreliable,becausetechnically

cookieis

easily

lostanddeleted

(suchasclearingbrowsercache,clearingWeChatcache,restartingWeChat).However,asanadditionalbarrier,itisstillrecommendedtoopenit.Graphicverificationcode:Theverificationcoderequiresvoterstoinputoranswersomegraphicsorquestionsthataredifficultformachinestorecognize.Inthisway,itcaneffectivelypreventcheatersfromusingcomputerprogramstosimulateautomaticvoting.Votingtimelimit:Forexample,thesameusercanonlycastonevotewithinthetimelimit.Votedobjectrestrictions:Forexample,thesameusercanonlyvoteforaspecifiednumberofvotedobjects.Otherrestrictions:Suchasrestrictinggeographiclocations,requiringuserstouseSMSverificationcodes,

etc.ProgrammingInoursystem,wesimulateseveralcommonvotingrestrictions.Thefirstoneisthatonepersoncanonlycast5votesforonevehicleaday.Whendesigningthedatabase,wespeciallydesignedatabletorecordthedetailsofvoting.Learningfromthisdatatable,wecanunderstandthehistoryofvoting,thereby

judgingwhetherthecurrentvotingmeetstherelevantconditions.

Thequeryguidelineisasfollows:thevotingtimeshouldbethecurrentday,theuserID

shouldbeIDofthecurrentregistrant,andthecarID

shouldbe

IDofthecurrentlyvotedvehicle.

Ifthisnumberofrecordsislessthan5,wecanvote,otherwisewecan'tvote.Thespecificoperationistoaddthefollowingcodebeforetheoriginalvotingcodeinvote.php:ProgrammingSummaryInthiscourse,wehaveaddedalimittovoting,thatis,onepersoncanonlycastamaximumof5votesforonevehicleaday.

Thisisjudgedbytherecordsinthevotedetailtable,queryingthenumberofrecordsthatthecurrentuservotedforthecurrentvehicletoday.Whenjudgingthetime,ifthevotingtimefieldtypeinthedatatableisdate,itcanbedirectly