ISO/IEC PRF 19075-6

Information technology -- Guidance for the use of database language SQL

Titre manque

General Information

• Status: Published
• ICS: 35.060 - Languages used in information technology
• Technical Committee: ISO/IEC JTC 1/SC 32 - Data management and interchange
• Drafting Committee: ISO/IEC JTC 1/SC 32/WG 3 - Database language

RELATIONS

• Revised: ISO/IEC TR 19075-6:2017 - Information technology -- Database languages -- SQL Technical Reports
• Effective Date: 23-Apr-2020

Standards Content (sample)

INTERNATIONAL ISO/IEC
STANDARD 19075-6
First edition
Information technology — Guidance
for the use of database language
SQL —
Part 6:
Support for JSON
PROOF/ÉPREUVE
Reference number
ISO/IEC 19075-6:2021(E)
ISO/IEC 2021
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ISO/IEC 19075-6:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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ISO/IEC19075-6:2021(E)
Contents Page

Foreword.....................................................................................ix

Introduction..................................................................................xi

1 Scope....................................................................................1

2 Normativereferences....................................................................2

3 Termsanddefinitions....................................................................3

4 JavaScriptObjectNotation(JSON)........................................................6

4.1 ContextforJSON........................................................................6

4.2 WhatisJSON?..........................................................................6

4.3 RepresentationsofJSONdata.............................................................7

4.3.1 IntroductiontorepresentationsofJSONdata................................................7

4.3.2 Avro..................................................................................7

4.3.3 BSON.................................................................................8

4.4 Schemas...............................................................................8

4.4.1 JSONschemataandvalidity...............................................................8

4.4.2 Avroschemata..........................................................................9

4.4.3 BSONschemata.........................................................................9

4.5 WhydoesJSONmatterinthecontextofSQL?WhatisJSON’srelationshiptoNoSQL?..............10

4.6 UsecasesforJSONsupportinSQL........................................................11

4.6.1 Introductiontotheusecases.............................................................11

4.6.2 JSONdataingestionandstorage..........................................................11

4.6.3 JSONdatagenerationfromrelationaldata..................................................11

4.6.4 QueryingJSONaspersistentsemi-structureddatamodelinstances.............................12

4.7 Whatfeaturesaddressthoseusecases?....................................................12

4.7.1 Addressingtheusecases................................................................12

4.7.2 StoringJSONdatainanSQLtable.........................................................12

4.7.3 GeneratingJSONinanSQLquery.........................................................12

4.7.4 QueryingJSONdatainSQLtablesusingSQL................................................13

5 TheSQL/JSONdatamodel..............................................................14

5.1 IntroductiontotheSQL/JSONdatamodel..................................................14

5.2 SQL/JSON items.......................................................................15

5.2.1 DefinitionofSQL/JSONitems............................................................15

5.2.2 Atomic values.........................................................................16

5.2.3 SQL/JSONarrays.......................................................................17

5.2.4 SQL/JSON objects......................................................................17

5.3 SQL/JSON sequences...................................................................17

5.4 Parsing JSON..........................................................................18

5.5 SerializingJSON........................................................................18

6 SQL/JSONfunctions.....................................................................19

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6.1 IntroductiontoSQL/JSONfunctions.......................................................19

6.2 HandleJSONusingbuilt-infunctions......................................................19

6.3 JSONAPIcommonsyntax................................................................19

6.3.1 IntroductiontoJSONAPIcommonsyntax..................................................19

6.3.2 JSONvalueexpression..................................................................20

6.3.3 Pathexpression........................................................................20

6.3.4 PASSING clause........................................................................20

6.3.5 JSONoutputclause.....................................................................21

6.3.6 ONERRORandONEMPTYsyntax.........................................................21

6.4 Queryfunctions........................................................................22

6.4.1 Thefourqueryfunctions................................................................22

6.4.2 JSON_EXISTS..........................................................................22

6.4.3 JSON_VALUE...........................................................................25

6.4.4 JSON_QUERY..........................................................................29

6.4.5 JSON_TABLE...........................................................................33

6.4.5.1 IntroductiontoJSON_TABLE............................................................33

6.4.5.2 COLUMNSclausethatisnotnested......................................................34

6.4.5.3 NestedCOLUMNSclause...............................................................36

6.4.5.4 PLAN clause.........................................................................37

6.4.6 Conformancefeaturesforqueryoperators.................................................41

6.5 ConstructorfunctionsandISJSONpredicate................................................43

6.5.1 TablesusedtoillustrateconstructorfunctionsandtheISJSONpredicate........................43

6.5.2 JSON_OBJECT..........................................................................44

6.5.3 JSON_OBJECTAGG......................................................................45

6.5.4 JSON_ARRAY..........................................................................46

6.5.5 JSON_ARRAYAGG.......................................................................47

6.5.6 ISJSONpredicate......................................................................49

6.5.7 HandlingofJSONnullsandSQLnulls......................................................49

6.5.8 Conformancefeaturesforconstructorfunctions.............................................50

7 SQL/JSONpathlanguage................................................................51

7.1 OverviewofSQL/JSONpathlanguage......................................................51

7.2 ObjectivesfortheSQL/JSONpathlanguage.................................................52

7.3 Modes................................................................................53

7.3.1 Introductiontomodes..................................................................53

7.3.2 Exampleofstrictvslax..................................................................54

7.4 Lexicalissues..........................................................................56

7.5 Syntaxsummary.......................................................................58

7.6 Formalsemanticsandnotationalconventions...............................................58

7.7 Primitiveoperationsinformalsemantics...................................................59

7.7.1 Concatenation.........................................................................59

7.7.2 unwrap().............................................................................59

7.7.3 wrap()...............................................................................60

7.8 Mode declaration......................................................................60

7.9 ...................................................................61

7.9.1 IntroductiontoJSONpathprimaries.......................................................61

7.9.2 Literals...............................................................................61

7.9.3 Variables.............................................................................62

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7.9.4 Parentheses...........................................................................63

7.10 Accessors.............................................................................63

7.10.1 Introductiontoaccessors................................................................63

7.10.2 Member accessor......................................................................64

7.10.3 Memberwildcardaccessor..............................................................67

7.10.4 Element accessor......................................................................68

7.10.5 Elementwildcardaccessor..............................................................70

7.10.6 Sequencesemanticsoftheaccessors......................................................71

7.11 Item methods.........................................................................71

7.11.1 Introductiontoitemmethods............................................................71

7.11.2 type()................................................................................72

7.11.3 size()................................................................................72

7.11.4 Numericitemmethods(double,ceiling,floor,abs)...........................................73

7.11.5 datetime()............................................................................73

7.11.6 keyvalue()............................................................................73

7.12 Arithmeticexpressions..................................................................75

7.12.1 Introductiontoarithmeticexpressions....................................................75

7.12.2 Unaryplusandminus...................................................................75

7.12.3 Binaryoperations......................................................................76

7.13 Filterexpression.......................................................................76

7.13.1 Introductiontofilterexpressions.........................................................76

7.13.2 true/falseandTrue/False.............................................................77

7.13.3 nullandUnknown.....................................................................78

7.13.4 Errorhandlinginfilters.................................................................78

7.13.5 Truthtables...........................................................................81

7.13.6 Comparisonpredicates..................................................................82

7.13.7 like_regexpredicate..................................................................83

7.13.8 starts withpredicate.................................................................84

7.13.9 exists predicate......................................................................84

7.13.10 is unknownpredicate..................................................................86

7.14 ConformancefeaturesforSQL/JSONpathlanguage..........................................87

Bibliography................................................................................88

Index........................................................................................89

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ISO/IEC19075-6:2021(E)
Tables
Table Page

1 JSON,SQL/JSON,andSQL(otherthanSQL/JSONvaluesandcounterparts)..........................14

2 ParallelsbetweenJSONtextandSQL/JSONdatamodel...........................................18

3 JSON_EXISTSsampledata...................................................................22

4 Resultofthesamplequery..................................................................23

5 Accessorexample..........................................................................24

6 Result1..................................................................................26

7 Result2..................................................................................26

8 Result3..................................................................................27

9 Result4..................................................................................27

10 Result5..................................................................................28

11 Result6..................................................................................29

12 JSON_EXISTSresults........................................................................30

13 ONEMPTYresults.........................................................................31

14 ARRAYWRAPPERresults...................................................................31

15 Illustratingdifferences......................................................................32

16 Comparisonofwrapperoptions..............................................................32

17 JSON_TABLEsampledatainabookrecommendationtable.......................................33

18 Unnestedqueryresult......................................................................35

19 Nestedqueryresult........................................................................36

20 PLANqueryresult.........................................................................39

21 SecondPLANqueryresult...................................................................39

22 ThirdPLANqueryresult....................................................................40

23 DEPTS table..............................................................................43

24 JOBStable................................................................................43

25 EMPLOYEEStable..........................................................................44

26 TheJSONobjectreturned...................................................................45

27 ReturnedJSONobjectwiththecorrespondingjobsequencenumber...............................46

28 ARRAYAGGqueryresult.....................................................................48

29 SecondARRAYAGGqueryresult..............................................................48

30 ThirdARRAYAGGqueryresult...............................................................49

31 Threeaspectsofpathevaluationgovernedbymodes............................................54

32 Exampleofstrictvslax.....................................................................55

33 FeaturesoftheSQL/JSONpathlanguage.......................................................58

34 Datausedbyunwrap()example..............................................................59

35 Datausedbywrap()example................................................................60

36 ExamplesofatomicvaluesintheSQL/JSONpathlanguage.......................................61

37 Examplesoftheescapingrules...............................................................61

38 Evaluationof'$.phones.type'inlaxmode...................................................65

39 Intermediatestep..........................................................................65

40 Evaluationof'$.phones[*].type'..........................................................66

41 Evaluationof'$.phones[*] ? (exists (@.type)).type'....................................66

42 Evaluationof'$.phones.*'inlaxmode......................................................67

43 Evaluationof '$.phones[*].*'.............................................................67

44 Evaluationof'lax $.sensors.*[0, last, 2]'..............................................69

45 Thestepintheevaluation..................................................................71

46 Resultofthequerywiththesampledata......................................................74

47 Evaluationof 'lax -$.readings.floor()'..................................................75

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48 Evaluationof'lax (-$.readings).floor()'................................................76

49 TableTwithtworows.....................................................................78

50 ComputationonrowK=102.................................................................79

51 ModifiedtableT...........................................................................79

52 ComputationonrowK=102inmodifiedtableT.................................................79

53 Computationof'lax $ ? (@.hours > 9)'onrowK=102.....................................80

54 Computationof'strict $ ? (@.hours > 9)'instrictmode..................................80

55 Resultof&&...............................................................................81

56 Resultof||...............................................................................81

57 Resultof!................................................................................81

58 Supportedcomparisons....................................................................82

59 Finalresult...............................................................................83

60 AtablewithJSONcolumn...................................................................85

61 Evaluationof'strict $ ? (exists (@.name)).name'onrowK=201..........................85

62 Evaluationof'strict $ ? (exists (@.name)).name'onrowK=202..........................85

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ISO/IEC19075-6:2021(E)
Figures
Figure Page

1 Relationshipsbetween“JSON”and“SQL/JSON”.................................................14

2 TheSQL/JSONpathlanguagearchitecture.....................................................51

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ISO/IEC19075-6:2021(E)
Foreword

ISO(theInternationalOrganizationforStandardization)andIEC(theInternationalElectrotechnical

Commission)formthespecializedsystemforworldwidestandardization.Nationalbodiesthatare

membersofISOorIECparticipateinthedevelopmentofInternationalStandardsthroughtechnical

committeesestablishedbytherespectiveorganizationtodealwithparticularfieldsoftechnicalactivity.

ISOandIECtechnicalcommitteescollaborateinfieldsofmutualinterest.Otherinternationalorganizations,

governmentalandnon-governmental,inliaisonwithISOandIEC,alsotakepartinthework.

Theproceduresusedtodevelopthisdocumentandthoseintendedforitsfurthermaintenanceare

describedintheISO/IECDirectives,Part1.Inparticular,thedifferentapprovalcriterianeededforthe

differenttypesofdocumentshouldbenoted.Thisdocumentwasdraftedinaccordancewiththeeditorial

rulesoftheISO/IECDirectives,Part2(seewww.iso.org/directivesorwww.iec.ch/mem-
bers_experts/refdocs).

Attentionisdrawntothepossibilitythatsomeoftheelementsofthisdocumentmaybethesubjectof

patentrights.ISOandIECshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights.Details

ofanypatentrightsidentifiedduringthedevelopmentofthedocumentwillbeintheIntroductionand/or

ontheISOlistofpatentdeclarationsreceived(seewww.iso.org/patents),ortheIEClistofpatent

declarationsreceived(seepatents.iec.ch).

Anytradenameusedinthisdocumentisinformationgivenfortheconvenienceofusersanddoesnot

constituteanendorsement.

Foranexplanationofthevoluntarynatureofstandards,themeaningofISOspecifictermsandexpressions

relatedtoconformityassessment,aswellasinformationaboutISO’sadherencetotheWorldTrade

Organization(WTO)principlesintheTechnicalBarrierstoTrade(TBT)seewww.iso.org/iso/fore-

word.html.IntheIEC,seewww.iec.ch/understanding-standards.

ThisdocumentwaspreparedbyTechnicalCommitteeISO/IECJTC1,Informationtechnology,Subcom-

mitteeSC32,Datamanagementandinterchange.

ThisfirsteditionofISO/IEC19075-6cancelsandreplacesISO/IECTR19075-6:2017.Severalsmall

technicalerrorshavebeencorrected,

ThisdocumentisintendedtobeusedinconjunctionwiththefollowingeditionsofthepartsoftheISO/IEC

9075series:
— ISO/IEC9075-1,sixtheditionorlater;
— ISO/IEC9075-2,sixtheditionorlater;
— ISO/IEC9075-3,sixtheditionorlater;
— ISO/IEC9075-4,seventheditionorlater;
— ISO/IEC9075-9,fiftheditionorlater;
— ISO/IEC9075-10,fiftheditionorlater;
— ISO/IEC9075-11,fiftheditionorlater;
— ISO/IEC9075-13,fiftheditionorlater;
— ISO/IEC9075-14,sixtheditionorlater;
— ISO/IEC9075-15,secondeditionorlater;
— ISO/IEC9075-16,firsteditionorlater.
©ISO/IEC2021–Allrightsreserved ix
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ISO/IEC19075-6:2021(E)
AlistofallpartsintheISO/IEC19075seriescanbefoundontheISOandIECwebsites.

Anyfeedbackorquestionsonthisdocumentshouldbedirectedtotheuser’snationalstandardsbody.A

completelistingofthesebodiescanbefoundatwww.iso.org/members.htmlandwww.iec.ch/-
national-committees.
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ISO/IEC19075-6:2021(E)
Introduction
Theorganizationofthisdocumentisasfollows:
1) Clause1,“Scope”,specifiesthescopeofthisdocument.

2) Clause2,“Normativereferences”,identifiesadditionalstandardsthat,throughreferenceinthis

document,constituteprovisionsofthisdocument.

3) Clause3,“Termsanddefinitions”,definesthetermsanddefinitionsusedinthisdocument.

4) Clause4,“JavaScriptObjectNotation(JSON)”,introduceswhatisJSON.
5) Clause5,“TheSQL/JSONdatamodel”,introducesthedatamodelthatisusedbytheSQL/JSON
functionsandtheSQL/JSONpathlanguage.

6) Clause6,“SQL/JSONfunctions”,introducestheSQL/JSONfunctionstoqueryandconstructJSON.

7) Clause7,“SQL/JSONpathlanguage”,introducestheSQL/JSONpathlanguage.
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ISO/IEC19075-6:2021(E)
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INTERNATIONAL STANDARD ISO/IEC 19075-6:2021(E)
Informationtechnology—GuidancefortheuseofdatabaselanguageSQL—
Part6:
SupportforJSON
1 Scope
ThisdocumentdescribesthesupportinSQLforJavaScriptObjectNotation.
ThisdocumentdiscussesthefollowingfeaturesoftheSQLlanguage:
— StoringJSONdata.
— PublishingJSONdata.
— QueryingJSONdata.
— SQL/JSONdatamodelandpathlanguage.
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ISO/IEC19075-6:2021(E)
2 Normativereferences

Thefollowingdocumentsarereferredtointhetextinsuchawaythatsomeoralloftheircontentconsti-

tutesrequirementsofthisdocument.Fordatedreferences,onlytheeditioncitedapplies.Forundated

references,thelatesteditionofthereferenceddocument(includinganyamendments)applies.

ISO/IEC9075-1,Informationtechnology—Databaselanguages—SQL—Part1:Framework
(SQL/Framework)
ISO/IEC9075-2,Informationtechnology—Databaselanguages—SQL—Part2:Foundation
(SQL/Foundation)
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ISO/IEC19075-6:2021(E)
3 Termsanddefinitions

Forthepurposesofthisdocument,thetermsanddefinitionsgiveninISO/IEC9075-1andthefollowing

termsanddefinitionsapply.

ISOandIECmaintainterminologicaldatabasesforuseinstandardizationatthefollowingaddresses:

— IECElectropedia:availableathttp://www.electropedia.org/
— ISOOnlinebrowsingplatform:availableathttp://www.iso.org/obp
3.1
JSONtext
sequenceoftokens

Note1toentry:JSONtextmustbeencodedinUnicode(UTF-8bydefault);insignificantwhitespacemay

beusedanywhereinJSONtextexceptwithinstrings(whereallwhitespaceissignificant),numbers,and

literals.JSONtextisasingleobjectorarray
3.2
token
strings,numbers,literals,oroneofsixstructuralcharacters
Note1toentry:Thesixstructuralcharactersare“{”,“}”,“[”,“]”,“:”,“,”
3.3
value
object,array,number,string,oroneofthreeliterals
3.4
type
primitivetypeorstructuredtype
3.5
primitivetype
string,number,Boolean,ornull
3.6
primitivevalue
valuethatisastring,number,Boolean,ornull
3.7
structuredtype
objectorarray
3.8
structuredvalue
valuethatisanobjectoranarray
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ISO/IEC19075-6:2021(E)
3 Termsanddefinitions
3.9
string
sequenceofUnicodecharacters

Note1toentry:Somecharactersmustbe“escaped”byprecedingthemwithareversesolidus(“\”),while

anyorallcharacterscanberepresentedin“Unicodenotation”comprisingthestring'\u'followedby

fourhexadecimaldigitsortwosuchstringsrepresentingtheUTF-16surrogatepairsrepresentingchar-

actersnotontheBasicMultilingualPlane.

Note2toentry: Stringsaresurroundedbydouble-quotecharacters,whicharenotpartofthevalueof

thestrings.
3.10
number

sequencecomprisinganintegerpart,optionallyfollowedbyafractionalpartand/oranexponentpart

Note1toentry:Non-numericvalues,suchasinfinityandNaNarenotpermitted.
3.11
Boolean
literal“true”orliteral“false”
3.12
null
literal“null”
3.13
object
structurerepresentedby“{”,zeroormoremembersseparatedby“,”,and“}”
3.14
member
stringfollowedbyacolonfollowedbyavalueinanobject

Note1toentry:Amemberisalsoknownasa“name-valuepair”;thenameissometimescalleda“key”

andthesecondvalueissometimescalleda“boundvalue”.
3.15
array
structurerepresentedbya“[”,zeroormoreelementsseparatedby“,”,and“]”
3.16
element
valueinanarray
3.17
field
memberinanobject,elementinanarray,nameinamember,orvalueinamember
3.18
datamodel

definitionofwhatkindsofdatabelongtoaparticularuniverseofdiscourse,includingthe

operationsonthosekindsofdata
3.19
JSONdatamodel
(implicit)datamodelassociatedwithJSON
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ISO/IEC19075-6:2021(E)
3 Termsanddefinitions
3.20
SQL/JSONdatamodel
datamodelcreatedforoperatingonJSONdatawithintheSQLlanguage
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ISO/IEC19075-6:2021(E)
4 JavaScriptObjectNotation(JSON)
4.1 ContextforJSON

TherequirementsforthematerialdiscussedinthisdocumentshallbeasspecifiedinISO/IEC9075-1

andISO/IEC9075-2.
4.2 WhatisJSON?

JSON(anacronymfor“JavaScriptObjectNotation”)isbothanotation(thatis,asyntax)forrepresenting

dataandanimplieddatamodel.JSONisnotanobject-orienteddatamodel;thatis,itdoesnotdefinesets

ofclassesandmethods,typeinheritance,ordataabstraction.Instead,JSON“objects”aresimpledata

structures,includingarrays.RFC8259saysthatJSONisatextformatfortheserializationofstructured

data.Itsinitialintendedusewasasadatatransfersyntax.
ThecompletesyntaxofJSONisspecifiedinRFC8259.

Thefirst-classcomponentsoftheJSONdatamodelareJSONvalues.AJSONvalueisoneofthefollowing:

JSONobject,JSONarray,JSONstring,JSONnumber,oroneoftheJSONliterals:true,false,andnull.AJSON

objectiszeroormorename-valuepairsandisenclosedincurlybraces—{ }.AJSONarrayisanordered

sequenceofzeroormorevaluesandisenclosedinsquarebrackets—[ ].
HereisanexampleofaJSONobject:
{ "Name" : "Isaac Newton",
"Weight" : 80,
"Famous" : true,
"Phone" : null }

Thename-valuepairsareseparatedbycommas,andthenamesareseparatedfromthevaluesbycolons.

Thenamesarealwaysstringsandareenclosedin(double)quotationmarks.
HereisanexampleofaJSONarray:
[ "Robert J. Oppenheimer", 98, false, "Beechwood 45789" ]

InaJSONarray,thevaluesareseparatedbycommas.JSONarraysandobjectsarefullynestable.Thatis,

valuesinbothJSONobjectsandJSONarraysmaybeJSONstrings,JSONnumbers,JSONBooleans(repre-

sentedbytheJSONliteralstrueandfalse),JSONnulls(representedbytheJSONliteralnull),JSONobjects,

orJSONarrays.

JSONcanbeusedtorepresentassociativearrays—arrayswhoseelementsareaddressedbycontent,

notbyposition.AnassociativearraycanberepresentedinJSONasaJSONobjectwhosemembersare

name-valuepairs;thenameisusedasthe“index”intothe“array”—thatis,tolocatetheappropriate

memberintheobject—andthevalueisusedasthecontentoftheappropriatemember.Hereissuchan

associativearray:
{ "Isaac Newton" : "apple harvester",
"Robert J. Oppenheimer": "security risk",
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4.2 WhatisJSON?
"Albert Einstein" : "patent clerk",
"Stephen Hawking" : "inspiration" }

AnextremelyimportantpartofJSON’sdesignisthatitisinherentlyschema-less.AnyJSONobjectcanbe

modifiedbyaddingnewname-valuepairs,evenwithnamesthatwereneverconsideredwhentheobject

wasinitiallycreatedordesigned.Similarly,anyJSONarraycanbemodifiedbychangingthenumberof

valuesinthearray.
4.3 RepresentationsofJSONdata
4.3.1 IntroductiontorepresentationsofJSONdata

Beforedelvingmuchdeeperintotheprimarytopicofthisdocument,readersshouldunderstandthat

JSONdatacanberepresentedinseveralwidely-acknowledgedand-usedforms.Themostobviousand

mosteasilyrecognizableisits“characterstring”representation,inwhichJSONdataisrepresentedin

Unicodecharactersasplaintext.Morespecifically,explicitcharacterssuchastheleftsquarebrace,

comma,rightcurlybrace,quotationmark,andlettersanddigitsareallusedintheirnativeUnicoderep-

resentation(UTF-8,UTF-16,UTF-32).

However,foravarietyofreasons,JSONdataissometimesstoredandexchangedinoneofseveralbinary

representations.Forexample,abinaryrepresentationofJSONdatamaybesignificantlysmaller(fewer

octets)thanthecharacterrepresentationofthesamedata,soareductioninnetworkbandwidthandor

storagemediacanbeachievedbytransferringorstoringthatdatainabinaryrepresentation.
Readersshouldnotethatt
...