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The nested set model is a technique for representing nested set collections (also known as trees or hierarchies) in relational databases.. It is based on Nested Intervals, that "are immune to hierarchy reorganization problem, and allow answering ancestor path hierarchical queries algorithmically — without accessing the stored hierarchy relation".
"The entity-relationship model adopts the more natural view that the real world consists of entities and relationships. It incorporates some of the important semantic information about the real world." [2] In his original 1976 article Chen explicitly contrasts entity–relationship diagrams with record modelling techniques:
For example, consider an address book entry that represents a single person along with zero or more phone numbers and zero or more addresses. This could be modeled in an object-oriented implementation by a "Person object " with an attribute/field to hold each data item that the entry comprises: the person's name, a list of phone numbers, and a ...
Overview of a data-modeling context: Data model is based on Data, Data relationship, Data semantic and Data constraint. A data model provides the details of information to be stored, and is of primary use when the final product is the generation of computer software code for an application or the preparation of a functional specification to aid a computer software make-or-buy decision.
There are several notations for data modeling. The actual model is frequently called "entity–relationship model", because it depicts data in terms of the entities and relationships described in the data. [4] An entity–relationship model (ERM) is an abstract conceptual representation of structured data.
Java 6, C++, CORBA Unknown Eclipse and MS VS.NET 2005 BOUML: Yes Yes Yes Yes C++, Java, PHP, IDL, Python, MySQL C++, Java, PHP, MySQL Unknown UML 2. Solid code roundtrip, fast. Extensible through "plug-outs" written in C++ or Java Cacoo: Yes Unknown Unknown Yes Unknown Unknown
The bridge pattern is often confused with the adapter pattern, and is often implemented using the object adapter pattern; e.g., in the Java code below. Variant: The implementation can be decoupled even more by deferring the presence of the implementation to the point where the abstraction is utilized.
The entity–relationship approach (E–R) of Peter Chen . The effort to develop IDEF1 resulted in both a new method for information modeling and an example of its use in the form of a "reference information model of manufacturing."