Components of ER

View the corresponding section of the Data Model

ERDiagram

View the corresponding section of the Data Model

An ER diagram is the graphical representation of a conceptual schema in the Entity Relationship Model.

There are two kinds of diagram:

Code	Short	Description
1	ER	Diagram in ER notation.
2	SER	Diagram in SER notation.

SER means Structured ER. This extension of ERM use the positions of entities in the diagram for semantic. The left entity of a relationship is a existence condition for the right entity. That means that the role to the right entity has got cardinality (1,1) and will not be displayed in the diagram.

See also:

Arguments for selects, infos and views on ERDiagram.

Modifying commands on ERDiagram.

ERDEntity

The entity node represents the occurance of an entity in an ER/SER diagram. Entities can occur in several diagrams as nodes.

See also:

Arguments for selects, infos and views on ERDEntity.

Modifying commands on ERDEntity.

ERDRelationship

The relationship nodes represents the occurance of a relationship in an ER/SER diagram. Relationships can occur in several diagrams as nodes.

See also:

Arguments for selects, infos and views on ERDRelationship.

Modifying commands on ERDRelationship.

PolyEREntRs

The entity relationship edge represents the occurrence of a role in an ER/SER diagram. Roles can occur in several diagrams as edges.

See also:

Arguments for selects, infos and views on PolyEREntRs.

Modifying commands on PolyEREntRs.

ERMEntity

View the corresponding section of the Data Model

Entities are concrete or abstract things for which information is to be collected. This information represents the features of the entities and is represented by attributes. Entities must be distinguishable, i.e. a single entity can be identified by specifying certain attribute values. Entities that can be described by the same attributes are combined into entity types. Individual entities are designated as entity specimens. Entities can have one of the following kinds:

code	Short	Description
1	E	An E type is an entity without existence condition.
2	ER	An ER type is an entity witht existence condition. That means each specimen of that entity has a mandatory reference to a specimen of another entity.
3	R	An R type is used to resolve m:n relationships or n-ary relationships.

See also:

Arguments for selects, infos and views on ERMEntity.

Modifying commands on ERDiagram.

ERMRelationship

In this context ERMRelationship is a collective notion for binary relationship or category.

A relationship connects two entities. The roles hold the description of the cardinaltity. If the relationship represents an existence condition, it can be marked as hierarchical.

Categories are used to represent superset/subset relationships. The category connects a superset entity (generalization) to subset entities (specializations). All categories are hierarchical relationships.

The relationship can be categorized by the following kinds:

Code	Short	Description
1	RS	Binary relationship.
2	ISA	ISA category, each specimen of the generalization entity must be referenced by a specimen of exactly one specialization entity (is a).
3	SUB	SUB category, each specimen of the generalization entity can be referenced by a specimen of at most one specialization entity.
4	OR	OR category, each specimen of the generalization entity can be referenced by a specimen of one or more specialization entities.

The code has been changed since INNOVATOR Version 6 !

See also:

Arguments for selects, infos and views on ERMRelationship.

Modifying commands on ERMRelationship.

ERMEntRs

A role is a connection between an entity and a relationship.

For binary relationships, the role annotation in (min,max)-notation is a precise method for describing the cardinality of relationships. (min,max)-notation means that an entity specimen must reference at least min specimens belonging to its linked entity and may reference no more than max specimens belonging to its linked entity.

Roles of categories need no information about cardinality, because the kind of category fix that. Exactly one role must be marked out belonging to the generalization entity.

See also:

Arguments for selects, infos and views on ERMEntRs.

Modifying commands on ERMEntRs.

ERMDBTable

Database tables describe how the entities of the data model are stored to relational databases.

View the corresponding section of the Data Model

Sometimes it is important to distinguish between the following kinds:

Code	Short	Description
1	C	The database table is directly derived from a C schema entity. The database table and the entity are using the same attributes.
2	D	The database table is not derived from C schema.
3	CD	The database table is derived from a C schema entity, but detached. The table references one or more entities.

See also:

Arguments for selects, infos and views on ERMDBTable.

Modifying commands on ERMDBTable.

ERMDBEntity

A CD database table owns at least one reference to an enity. The first one is the reference to the leading entity which contains no information about a role. Further entity references can be merged into the database table via relationships. In this case the role to that entity is stored within the entity reference.

See also:

Arguments for infos and views on ERMDBEntity.

Modifying commands on ERMDBEntity.

ERMSpecimen

Entities which have a relationship to an entity referenced by a CD database table can be merged to this table. It depends on the cardinality of the relationship how many specimen of this entity can occur in the table.

See also:

Arguments for infos and views on ERMSpecimen.

ERConstraint

Constraints are used to validate the elements of the entity relationship model. They can be assigned to entities or database tables.

See also:

Arguments for selects, infos and views on ERConstraint.

Modifying commands on ERConstraint.

ERConTab

The constraint table assignment represents the assignment of a constraint to an entity or a database table. Each assignment contains the information at which time and for which operations the constraint has to be evaluated.

See also:

Arguments for infos and views on ERConTab.

ERMAttribute

Enitities or database tables are collections of attributes. An attribute can be part of an entity and a C database table at the same time!

View the corresponding section of the Data Model

For schema membership look at the following codes:

Code	Short	Description
1	C	The attribute is part of an entity - C schema.
2	D	The attribute is part of an database table - D schema.
3	CD	The attribute is part of an entity and an C database table.

See also:

Arguments for selects, infos and views on ERMAttribute.

Modifying commands on ERMAttribute.

ERMPrimKey

The primary key is the unambiguous identifier for a database table. Each primary key contains at least one attribute.

See also:

Arguments for infos and views on ERMPrimKey.

Modifying commands on ERMPrimKey.

ERMForKey

Foreign keys represent the relationship between database tables. Each foreign key contains at least one attribute which is connected to a primary key attribute of a related database table.

See also:

Arguments for infos and views on ERMForKey.

Modifying commands on ERMForKey.

ERMPkFk

This class implements the link of an foreign key attribute to one primary key attribute.

ERMIndex

Indices are used to find database table entries by the values of a list of attributes. An index contains at least one attribute. Indices with a maximum of one database table entries for each value are called unique.

See also:

Arguments for infos and views on ERMIndex.

Modifying commands on ERMIndex.

ERMIndAttr

Index attributes represent the connection of attributes to an index.

See also:

Arguments for views on ERMIndAttr.

ERMAttrSpec

Entities that have a relationship to the leading entity of a database table can be merged to the table. It depends on the cardinality of the relationship how many specimen of this entity and its attributes can occur in the table.

See also:

Arguments for infos and views on ERMAttrSpec.

ERMTabOpt

The table option represents options that are used for the implementation of tables in a target system.

See also:

Arguments for infos on ERMTabOpt.

ERMAttrOpt

The attribute option represents options that are used for the implementation of attributes in a target system.

See also:

Arguments for infos on ERMAttrOpt.

ERMPrimOpt

The primary key option represents options that are used for the implementation of primary keys in a target system.

See also:

Arguments for infos on ERMPrimOpt.

ERMForOpt

The foreign key option represents options that are used for the implementation of foreign keys in a target system.

See also:

Arguments for infos on ERMForOpt.

ERMIndOpt

The index option represents options that are used for the implementation of indices in a target system.

See also:

Arguments for infos on ERMIndOpt.

ERMIaOpt

The index attribute option represents options that are used for the implementation of index attributes in a target system.

See also:

Arguments for infos on ERMIaOpt.

ERMDataElement

View the corresponding section of the Data Model

Attributes of an ER entity can be typified by a data element.

See also:

Arguments for selects, infos and views on ERMDataElement.

Modifying commands on ERMDataElement.

ERMDeTable

The data elements can be organized in data element tables.

See also:

Arguments for selects, infos and views on ERMDeTable.

Modifying commands on ERMDeTable.

TargetSystem

The target system is a programming language or a database in which the ERM/SERM is implemented. It is possible to implement the model in several target systems at the same time. The elements will be loaded from the inots.ini file.

See also:

Arguments for selects, infos and views on TargetSystem.

TSOption

TSOption represents options that are used for the implementation of elements in a target system. The elements will be loaded from the inots.ini file.

The following list shows the possible kinds of elements for which options can be defined:

Code	Element	inots.ini entry
1	Database Table	table
2	Attribute	attribute
3	Primary Key	primary key
4	Foreign Key	foreign key
5	Index	index
6	Index Attribute	index attribute

See also:

Arguments for selects and infos on TSOption.

ERMDBView

Database views are used for restricted view on the database. They will be defined on database tables or other database views.

See also:

Arguments for selects, infos and views on ERMDBView.

Modifying commands on ERMDBView.

ERMDBVColumn

Database views are collections of columns. These columns will be definde as an expression using databas table attributes or other database view columns.

See also:

Arguments for selects, infos and views on ERMDBVColumn.

Modifying commands on ERMDBVColumn.

ERMDBVFrom

A from clause of a database view shows, which database table or database view is used for view columns or where clauses.

See also:

Arguments for selects, infos and views on ERMDBVFrom.

Modifying commands on ERMDBVFrom.

ERMViewOpt

The view option represents options that are used for the implementation of database views in a target system.

See also:

Arguments for infos on ERMViewOpt.

ERMColOpt

The column option represents options that are used for the implementation of database view columns in a target system.

See also:

Arguments for infos on ERMColOpt.

ERMFromOpt

The from option represents options that are used for the implementation of database view from clause in a target system.

See also:

Arguments for infos on ERMFromOpt.