Search results
Results from the WOW.Com Content Network
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".
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 ...
The entity–relationship model proposes a technique that produces entity–relationship diagrams (ERDs), which can be employed to capture information about data model entity types, relationships and cardinality. A Crow's foot shows a one-to-many relationship. Alternatively a single line represents a one-to-one relationship. [4]
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
For example, we can indicate, using an arrowhead that the pointy end is visible from the arrow tail. We can indicate ownership by the placement of a ball, the role the elements of that end play by supplying a name for the role, and the multiplicity of instances of that entity (the range of number of objects that participate in the association ...
[8] 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.
Rather, they show entity sets (all entities of the same entity type) and relationship sets (all relationships of the same relationship type). For example, a particular song is an entity, the collection of all songs in a database is an entity set, the eaten relationship between a child and his lunch is a single relationship, and the set of all ...
Defining objects, creating class diagram from conceptual diagram: Usually map entity to class. Identifying attributes and their models. Use design patterns (if applicable): A design pattern is not a finished design, it is a description of a solution to a common problem, in a context. [7]