1. 1 ODMG

2. 2 Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments

3. 3 ODMG Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments R.G.C. Cattell The Object Database Standard : ODMG, Release 1.2, 1996 Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments R.G.C. Cattell The Object Database Standard : ODMG, Release 1.2, 1996

4. 4 ODMG Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments R.G.C. Cattell The Object Database Standard : ODMG, Release 1.2, 1996 R.G.C. Cattell, D.K. Barry The Object Database Standard: ODMG 2.0, 1997 Object Database Management Group (ODMG) ODMG has been formed in late 1991 by: ObjectDesign, Ontos, O2 Technology, Versant, Objectivity, Digital Equipment, Hewlett-Packard, Itasca, Intellitic, Poet Software, Servio, Texas Instruments R.G.C. Cattell The Object Database Standard : ODMG, Release 1.2, 1996 R.G.C. Cattell, D.K. Barry The Object Database Standard: ODMG 2.0, 1997

5. 5 ODMG Aims To put forward a set of standards allowing an ODBMS customer to write portable applications, i.e. application that could run on more than one ODBMS Aims To put forward a set of standards allowing an ODBMS customer to write portable applications, i.e. application that could run on more than one ODBMS

6. 6 ODMG ODMG versus Relational DBMS

7. 7 ODMG ODMG versus Relational DBMS

8. 8 ODMG Architecture

9. 9 ODMG Architecture

10. 10 ODMG Components

11. 11 ODMG Components  Framework A portion of ODMG that is common to all programming languages Components  Framework A portion of ODMG that is common to all programming languages

12. 12 ODMG Components  Framework A portion of ODMG that is common to all programming languages Framework consist of: »Object Model »Object Definition Language »Object Query Language Components  Framework A portion of ODMG that is common to all programming languages Framework consist of: »Object Model »Object Definition Language »Object Query Language

13. 13 ODMG Components  Bindings Bindings for each programming language in which ODBMS is used (currently: C++, Smalltalk) Components  Bindings Bindings for each programming language in which ODBMS is used (currently: C++, Smalltalk)

14. 14 ODMG Basic concepts

15. 15 ODMG Basic concepts  The model is based on objects with object identifiers Basic concepts  The model is based on objects with object identifiers

16. 16 ODMG Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types

17. 17 ODMG Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types  The behaviour of objects is defined by a set of operations Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types  The behaviour of objects is defined by a set of operations

18. 18 ODMG Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types  The behaviour of objects is defined by a set of operations  The state of objects is determined by a set of properties (attributes, relationships) Basic concepts  The model is based on objects with object identifiers  Objects are categorised into types  The behaviour of objects is defined by a set of operations  The state of objects is determined by a set of properties (attributes, relationships)

19. 19 ODMG Basic concepts  Each object may have a unique name Basic concepts  Each object may have a unique name

20. 20 ODMG Basic concepts  Each object may have a unique name  Operations are defined by operation signatures Basic concepts  Each object may have a unique name  Operations are defined by operation signatures

21. 21 ODMG Basic concepts  Each object may have a unique name  Operations are defined by operation signatures  Attributes are defined by attribute signatures Basic concepts  Each object may have a unique name  Operations are defined by operation signatures  Attributes are defined by attribute signatures

22. 22 ODMG Basic concepts  Each object may have a unique name  Operations are defined by operation signatures  Attributes are defined by attribute signatures  Relationships are specified by relationship signatures Basic concepts  Each object may have a unique name  Operations are defined by operation signatures  Attributes are defined by attribute signatures  Relationships are specified by relationship signatures

23. 23 ODMG Basic concepts  Collection types include sets, bags, lists and arrays Basic concepts  Collection types include sets, bags, lists and arrays

24. 24 ODMG Basic concepts  Collection types include sets, bags, lists and arrays  Object types are related in subtype/supertype graph Basic concepts  Collection types include sets, bags, lists and arrays  Object types are related in subtype/supertype graph

25. 25 ODMG Basic concepts  Collection types include sets, bags, lists and arrays  Object types are related in subtype/supertype graph  An extent set can be declared to contain all instances of a given type Basic concepts  Collection types include sets, bags, lists and arrays  Object types are related in subtype/supertype graph  An extent set can be declared to contain all instances of a given type

26. 26 ODMG Basic concepts  Individual instances can be uniquely identified by the value they carry for some property or set of properties (keys) Basic concepts  Individual instances can be uniquely identified by the value they carry for some property or set of properties (keys)

27. 27 ODMG Type hierarchy

28. 28 ODMG Type hierarchy

29. 29 ODMG Object Definition Language

30. 30 ODMG Object Definition Language Employee Teaching Assistant Professor Section Student Course teaches is taught by assists has TA has prerequisites is prerequisite belongs to consists of has of

31. 31 ODMG Object Definition Language interface Course (extent courses keys name, number ) Object Definition Language interface Course (extent courses keys name, number )

32. 32 ODMG Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number;

33. 33 ODMG Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number }; Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number };

34. 34 ODMG Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number }; relationship Set has_prerequisites inverse Course::is_prerequisite_for; Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number }; relationship Set has_prerequisites inverse Course::is_prerequisite_for;

35. 35 ODMG Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number }; relationship Set has_prerequisites inverse Course::is_prerequisite_for; relationship Set is_prerequisite_for inverse Course::has_prerequisites; Object Definition Language interface Course (extent courses keys name, number ) { attribute String name; attribute String number; relationship List has_sections inverse Section::is_section_of { order by Section::number }; relationship Set has_prerequisites inverse Course::is_prerequisite_for; relationship Set is_prerequisite_for inverse Course::has_prerequisites;

36. 36 ODMG Object Definition Language Boolean offer( in Unsigned Short semester) raises(already_offered); Boolean drop( in Unsigned Short semester) raises(not_offered); }; Object Definition Language Boolean offer( in Unsigned Short semester) raises(already_offered); Boolean drop( in Unsigned Short semester) raises(not_offered); };

37. 37 ODMG Object Definition Language interface Section (extent sections key (is_section_of, number) ) Object Definition Language interface Section (extent sections key (is_section_of, number) )

38. 38 ODMG Object Definition Language interface Section (extent sections key (is_section_of, number) ) { attribute String number; relationship Professor is_taught_by inverse professor::teaches; relationship TA has_TA inverse TA::assists; relationship Course is_section_of inverse Course::has_sections; relationship Set is_taken_by inverse Student::takes; }; Object Definition Language interface Section (extent sections key (is_section_of, number) ) { attribute String number; relationship Professor is_taught_by inverse professor::teaches; relationship TA has_TA inverse TA::assists; relationship Course is_section_of inverse Course::has_sections; relationship Set is_taken_by inverse Student::takes; };

39. 39 ODMG Object Definition Language interface Employee (extent employees key (name. id) ) { attribute String name; attribute Short id; attribute Unsigned Short annual_salary; void hire(); void fire() raises (no_such_employee); }; Object Definition Language interface Employee (extent employees key (name. id) ) { attribute String name; attribute Short id; attribute Unsigned Short annual_salary; void hire(); void fire() raises (no_such_employee); };

40. 40 ODMG Object Definition Language interface Professor:Employee (extent professors ) {attribute Enum Rank { full, associate, assistant} ; relationship Set teaches inverse section::is_taught_by; Short grant_tenure() raises(ineligible_for tenure); } interface TA: Employee, Student() { relationship Section assists inverse Section::has_TA; }; Object Definition Language interface Professor:Employee (extent professors ) {attribute Enum Rank { full, associate, assistant} ; relationship Set teaches inverse section::is_taught_by; Short grant_tenure() raises(ineligible_for tenure); } interface TA: Employee, Student() { relationship Section assists inverse Section::has_TA; };

41. 41 ODMG Object Definition Language interface Student (extent students keys name, student_id ) {attribute String name; attribute String student_id; attribute Struct Address {String college, String room_number, } dorm_address; relationship Set takes inverse Section::is_taken_by; Object Definition Language interface Student (extent students keys name, student_id ) {attribute String name; attribute String student_id; attribute Struct Address {String college, String room_number, } dorm_address; relationship Set takes inverse Section::is_taken_by;

42. 42 ODMG Object Definition Language) Boolean register_for_course( in Unsigned Short Course, in Unsigned Short Section ) raises(unsatisfied_prerequisites, section_full, course_full ); void drop_course( in Unsigned Short Course ) raises( not_registered_for_that_course); void assign_major( in Unsigned Short Department ); Object Definition Language) Boolean register_for_course( in Unsigned Short Course, in Unsigned Short Section ) raises(unsatisfied_prerequisites, section_full, course_full ); void drop_course( in Unsigned Short Course ) raises( not_registered_for_that_course); void assign_major( in Unsigned Short Department );

43. 43 ODMG Object Definition Language Short transfer( in Unsigned Short old_section, in Unsigned Short new_section ); }; Object Definition Language Short transfer( in Unsigned Short old_section, in Unsigned Short new_section ); };

44. 44 ODMG Programming language (C++) binding

45. 45 ODMG Programming language (C++) binding  There is single unified type system across the programming language and the database Programming language (C++) binding  There is single unified type system across the programming language and the database

46. 46 ODMG Programming language (C++) binding  There is single unified type system across the programming language and the database  The programming language-specific binding for ODL/OML respects the syntax and semantics of the base programming language into which it is being inserted Programming language (C++) binding  There is single unified type system across the programming language and the database  The programming language-specific binding for ODL/OML respects the syntax and semantics of the base programming language into which it is being inserted

47. 47 ODMG Programming language (C++) binding  There is single unified type system across the programming language and the database  The programming language-specific binding for ODL/OML respects the syntax and semantics of the base programming language into which it is being inserted  The binding is structured as a small set of additions to the base programming language Programming language (C++) binding  There is single unified type system across the programming language and the database  The programming language-specific binding for ODL/OML respects the syntax and semantics of the base programming language into which it is being inserted  The binding is structured as a small set of additions to the base programming language

48. 48 ODMG Programming language (C++) binding  Expressions in OML compose freely with expressions from the base programming language and vice versa Programming language (C++) binding  Expressions in OML compose freely with expressions from the base programming language and vice versa

49. 49 ODMG C++ binding

50. 50 ODMG C++ binding  Persistent-capable classes class Professor : public Persistent_Object C++ binding  Persistent-capable classes class Professor : public Persistent_Object

51. 51 ODMG C++ binding  Persistent-capable classes class Professor : public Persistent_Object { public: Ref dept inverse Department::professors; C++ binding  Persistent-capable classes class Professor : public Persistent_Object { public: Ref dept inverse Department::professors;

52. 52 ODMG C++ binding  Persistent-capable classes class Professor : public Persistent_Object { public: Ref dept inverse Department::professors; Set > advises inverse Student::advisor; }; C++ binding  Persistent-capable classes class Professor : public Persistent_Object { public: Ref dept inverse Department::professors; Set > advises inverse Student::advisor; };

53. 53 ODMG C++ binding  Ref-based approach For each persistence-capable class T, an ancillary class Ref is defined C++ binding  Ref-based approach For each persistence-capable class T, an ancillary class Ref is defined

54. 54 ODMG C++ binding  Ref-based approach For each persistence-capable class T, an ancillary class Ref is defined Ref profP; Ref deptRef; profP->grant_tenure(); deptRef = profP->dept; C++ binding  Ref-based approach For each persistence-capable class T, an ancillary class Ref is defined Ref profP; Ref deptRef; profP->grant_tenure(); deptRef = profP->dept;

55. 55 ODMG Mapping ODMG Model into C++

56. 56 ODMG Mapping ODMG Model into C++  Object type -> C++ class Mapping ODMG Model into C++  Object type -> C++ class

57. 57 ODMG Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class

58. 58 ODMG Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class  Collections -> template classes Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class  Collections -> template classes

59. 59 ODMG Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class  Collections -> template classes template class Set: public Collection {...}; class Ship {...}; Set > Cunard_Line; Mapping ODMG Model into C++  Object type -> C++ class  Structure ->struct or class  Collections -> template classes template class Set: public Collection {...}; class Ship {...}; Set > Cunard_Line;

60. 60 ODMG Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes

61. 61 ODMG Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions

62. 62 ODMG Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions  relationships -> methods that traverse relationship Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions  relationships -> methods that traverse relationship

63. 63 ODMG Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions  relationships -> methods that traverse relationship  arrays of objects -> Varray C++ class Mapping ODMG Model into C++  subtype/supertype hierarchy -> hierarchy of classes  operations -> C++ functions  relationships -> methods that traverse relationship  arrays of objects -> Varray C++ class

64. 64 ODMG Mapping ODMG Model into C++  keys -> ?  extents -> ?  name -> ? Mapping ODMG Model into C++  keys -> ?  extents -> ?  name -> ?

65. 65 ODMG C++ ODL

66. 66 ODMG C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone; C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone;

67. 67 ODMG C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone; struct {intPO_box; Stringuniversity; Stringcity; Stringstate; Stringzip_code; } university_address; C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone; struct {intPO_box; Stringuniversity; Stringcity; Stringstate; Stringzip_code; } university_address;

68. 68 ODMG C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone; struct {intPO_box; Stringuniversity; Stringcity; Stringstate; Stringzip_code; } university_address; List favorite_friends; }; C++ ODL  Attributes class Student : public Persistent_Object {Stringname; Datebirth_date; Phone_Numberdorm_phone; struct {intPO_box; Stringuniversity; Stringcity; Stringstate; Stringzip_code; } university_address; List favorite_friends; };

69. 69 ODMG C++ ODL  Relationships class Department : public Persistent_Object { public: Set > professors inverse Professor::dept; }; C++ ODL  Relationships class Department : public Persistent_Object { public: Set > professors inverse Professor::dept; };

70. 70 ODMG C++ ODL  Relationships class Department : public Persistent_Object { public: Set > professors inverse Professor::dept; }; class Professor : public Persistent_Object { Ref dept inverse Department::professors; Set > advisees inverse Student::advisor; }; C++ ODL  Relationships class Department : public Persistent_Object { public: Set > professors inverse Professor::dept; }; class Professor : public Persistent_Object { Ref dept inverse Department::professors; Set > advisees inverse Student::advisor; };

71. 71 ODMG C++ ODL  Relationships class Student : public Persistent_Object { public: Ref advisor inverse Professor::advisees; Set > classes inverse Course::students_enrolled; }; C++ ODL  Relationships class Student : public Persistent_Object { public: Ref advisor inverse Professor::advisees; Set > classes inverse Course::students_enrolled; };

72. 72 ODMG C++ ODL  Relationships class Student : public Persistent_Object { public: Ref advisor inverse Professor::advisees; Set > classes inverse Course::students_enrolled; }; class Course : public Persistent_Object {public: Set > students_enrolled inverse Student::classes; }; C++ ODL  Relationships class Student : public Persistent_Object { public: Ref advisor inverse Professor::advisees; Set > classes inverse Course::students_enrolled; }; class Course : public Persistent_Object {public: Set > students_enrolled inverse Student::classes; };

73. 73 ODMG C++ ODL  Unidirectional Relationships struct Responsible { Stringdept; Ref e; Datedue_date; }; C++ ODL  Unidirectional Relationships struct Responsible { Stringdept; Ref e; Datedue_date; };

74. 74 ODMG C++ ODL  Unidirectional Relationships struct Responsible { Stringdept; Ref e; Datedue_date; }; class Order { public: Set >who; Stringwhat; Responsiblecontact; }; C++ ODL  Unidirectional Relationships struct Responsible { Stringdept; Ref e; Datedue_date; }; class Order { public: Set >who; Stringwhat; Responsiblecontact; };

75. 75 ODMG C++ ODL  Object Creation static const Database * const Database::transient_memory; C++ ODL  Object Creation static const Database * const Database::transient_memory;

76. 76 ODMG C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0); C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0);

77. 77 ODMG C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0); (ii)void * operator new( size_t size, constRef &clustering, const char* typename =0); C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0); (ii)void * operator new( size_t size, constRef &clustering, const char* typename =0);

78. 78 ODMG C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0); (ii)void * operator new( size_t size, constRef &clustering, const char* typename =0); (iii)void * operator new( size_t size, Database * database, const char* typename =0); C++ ODL  Object Creation static const Database * const Database::transient_memory; Forms of new operator: (i)void * operator new( size_t size, const char* typename = 0); (ii)void * operator new( size_t size, constRef &clustering, const char* typename =0); (iii)void * operator new( size_t size, Database * database, const char* typename =0);

79. 79 ODMG C++ ODL  Object creation Database *yourDB, *myDB; C++ ODL  Object creation Database *yourDB, *myDB;

80. 80 ODMG C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule; C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule;

81. 81 ODMG C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule; Ref prof2 = new( yourDB, "Professor") Professor; C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule; Ref prof2 = new( yourDB, "Professor") Professor;

82. 82 ODMG C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule; Ref prof2 = new( yourDB, "Professor") Professor; Ref student1 = new(myDB) Student; Ref student2 = new(student1) Student; Ref temp_student = new(Database::transient_memory) Student; C++ ODL  Object creation Database *yourDB, *myDB; Ref temp_sched1 = new Schedule; Ref prof2 = new( yourDB, "Professor") Professor; Ref student1 = new(myDB) Student; Ref student2 = new(student1) Student; Ref temp_student = new(Database::transient_memory) Student;

83. 83 ODMG C++ ODL  Object Deletion Ref obj_ref; // set obj_ref to refer to persistent object obj_ref.delete_object(); C++ ODL  Object Deletion Ref obj_ref; // set obj_ref to refer to persistent object obj_ref.delete_object();

84. 84 ODMG C++ ODL  Object Deletion Ref obj_ref; // set obj_ref to refer to persistent object obj_ref.delete_object();  Object Modification obj_ref->mark_modified(); C++ ODL  Object Deletion Ref obj_ref; // set obj_ref to refer to persistent object obj_ref.delete_object();  Object Modification obj_ref->mark_modified();

85. 85 ODMG C++ ODL  Object References –Object references are instances of Ref C++ ODL  Object References –Object references are instances of Ref

86. 86 ODMG C++ ODL  Object References –Object references are instances of Ref –All accesses to persistent objects are made via methods defined on classes Ref, Persistent_Object, Database C++ ODL  Object References –Object references are instances of Ref –All accesses to persistent objects are made via methods defined on classes Ref, Persistent_Object, Database

87. 87 ODMG C++ ODL  Object References –Object references are instances of Ref –All accesses to persistent objects are made via methods defined on classes Ref, Persistent_Object, Database –The dereference operator -> is used to access members of the persistent object "addressed" by a given object reference C++ ODL  Object References –Object references are instances of Ref –All accesses to persistent objects are made via methods defined on classes Ref, Persistent_Object, Database –The dereference operator -> is used to access members of the persistent object "addressed" by a given object reference

88. 88 ODMG C++ ODL  Attributes prof->id_number = next_id; cout id_number; C++ ODL  Attributes prof->id_number = next_id; cout id_number;

89. 89 ODMG C++ ODL  Relationships 1-1 class A {Ref inverse B::ra } class B {Ref inverse ::rb; } C++ ODL  Relationships 1-1 class A {Ref inverse B::ra } class B {Ref inverse ::rb; }

90. 90 ODMG C++ ODL  Relationships 1-1 class A {Ref inverse B::ra } class B {Ref inverse ::rb; } a.rb = &b;//add relationship a.rb.clear();// remove relationship a.rb = &bb; //modify relationship C++ ODL  Relationships 1-1 class A {Ref inverse B::ra } class B {Ref inverse ::rb; } a.rb = &b;//add relationship a.rb.clear();// remove relationship a.rb = &bb; //modify relationship

91. 91 ODMG C++ ODL  Relationships 1:M class A {Set > sb inverse B::ra; } class B {Ref ra inverse A::sb; } C++ ODL  Relationships 1:M class A {Set > sb inverse B::ra; } class B {Ref ra inverse A::sb; }

92. 92 ODMG C++ ODL  Relationships 1:M class A {Set > sb inverse B::ra; } class B {Ref ra inverse A::sb; } a.sb.insert_element(&b); // add relationship a.sb.remove_element(&b); // remove relationship. or b.ra.clear(); b.ra = &&aa; // modify relationship C++ ODL  Relationships 1:M class A {Set > sb inverse B::ra; } class B {Ref ra inverse A::sb; } a.sb.insert_element(&b); // add relationship a.sb.remove_element(&b); // remove relationship. or b.ra.clear(); b.ra = &&aa; // modify relationship

93. 93 ODMG C++ ODL  Relationships M:N class A {Set > sb inverse B::sa; } class B {Set > sa inverse A:sb; } C++ ODL  Relationships M:N class A {Set > sb inverse B::sa; } class B {Set > sa inverse A:sb; }

94. 94 ODMG C++ ODL  Relationships M:N class A {Set > sb inverse B::sa; } class B {Set > sa inverse A:sb; } a.sb.insert_element(&b); // add relationship a.sb.remove_element(&b); // remove relationship or b.sa.remove_element(&a); a.sb.replace_element_at(&bb, 3);// modify relationship C++ ODL  Relationships M:N class A {Set > sb inverse B::sa; } class B {Set > sa inverse A:sb; } a.sb.insert_element(&b); // add relationship a.sb.remove_element(&b); // remove relationship or b.sa.remove_element(&a); a.sb.replace_element_at(&bb, 3);// modify relationship