Data Modeling Language Information Engineering-ie model

Information engineering uses Crow's foot notation (also known as James Martin Notation), in Chinese translation the use of crow ' s The model of the foot representation is also broadly called the Duck Web model (The associated cardinality of the correlation relation is represented by a duck web-shaped triangular line). He was invented by Clive Finkelstein, and was promoted with James Martin, who later made a couple of amendments to form two versions.

The information engineering of the preceding example model is represented as follows:

Figure:information engineering-ie model -Crow ' s Foot model- Duck Web Models diagram: Information Engineering-ie model

NoteIEmodel andERthe difference between models. Purchase Orderwith the Partyis many-to-oneN:1the correlation between theERin the ModelNwas placed in the Partythe left, whileIEin the ModelNwas placed in thePurchase Orderto the right. The form of two representations (equivalent to syntax) is different, but the semantics are consistent. This is onlyERmodels are special, and other model representations areIEmodel Consistent
entity & Attribute : Entity properties do not appear in in the model, instead of using separate documents to record
relationship
Crow ' s Foot optional optionality cardinality 

Figure:Crow ' s Footthe options availableoptionalityand associated cardinalitycardinalityrepresentation diagram:Crow ' s Footthe options availableoptionalityand associated cardinalitycardinalitynotation

optionality options available: Used to indicate whether the association is optional or required. For an optional association relationship, the foreign key field that is used for the association is usually allowed to be null , or the associated data may not appear for the use of an intermediate association relation table, and the required association does not allow the foreign key to be null Or there must be associated data
cardinality Correlation Cardinality: The maximum number of objects used to represent an associated entity, 1,n , etc.
the right part of the diagram shows the following meanings:1aAmust be associated to1one or moreB, aBcan be associated0one or1aA

The associated constraints,Productand theServiceconnect through a circle toOrder Line. If it is a solid circle, it indicatesProductand theServiceis aExclusive ORand if it's a hollow circle, it meansProductand theServiceis ainclusive or(Compatible,conjunctive), which means that one or more of these can be
on topIEin the model diagram,Order LineRight isFinkelsteinA special symbol that represents aPurchase OrderInitially, there0orNaOrder Line, but eventually there must be1orNaOrder Line
MartinName the association with a verb, name only one Direction (follow the way from left to right, top down), and Finkelstein not name the association

sub-type : party martin adopted, finkelstein isa isa UML inherited triangles conform, using a triangle on the association line) to represent them as subclasses

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Data Modeling Language Information Engineering-ie model