Bachman diagram

Bachman diagram

Bachman diagrams are diagrams which are used to design the data using a network or relational "logical" model, separating the data model from the way the data is stored in the system. The model is named after database pioneer Charles Bachman, and mostly used in computer software design. A bachman diagram is another name for a data structure diagram. [ [http://www.irs.gov/irm/part2/ch04s15.html IRS Resources] . Part 2. Information Technology, Chapter 5. Systems Development, Section 13. Database Design Techniques and Deliverables. Retrieved 20 July 2008.]

In a relational model a relation is the cohesion of attributes that are fully and not transitive functional dependent of every key in that relation. The coupling between the relations is based on accordant attributes. For every relation a rectangle has to be drawn and every coupling is illustrated by a line that connects the relations. On the edge of each line arrows indicate the cardinality. We have 1-to-n, 1-to-1 and n-to-m. The latter has to be avoided and must be replaced by two 1-to-n couplings.

ee also

*Entity-relationship model

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Bachman — may refer to:* Bachman Khan (1210 ndash;1239 or 1240), a Kimak khan *an anglicized spelling of the surname Bachmann: ** John Bachman (1790 ndash;1874), American naturalist ** Charlie Bachman (1892 ndash;1985), Hall of Fame college football coach… …   Wikipedia

  • Diagram — Further information: Chart Sample flowchart representing the decision process to add a new article to Wikipedia. A diagram is a two dimensional geometric symbolic representation of information according to some visualization technique. Sometimes …   Wikipedia

  • Charles Bachman — Not to be confused with Charles A. Bachman. Charles W. Bachman Charles Bachman at the IUA Workshop, 2006 …   Wikipedia

  • Network diagram — A network diagram is a general type of diagram, which represents some kind of network. A network in general is an interconnected group or system, or a fabric or structure of fibrous elements attached to each other at regular intervals.A network… …   Wikipedia

  • Data structure diagram — Example of a Data Structure Diagram. A Data Structure Diagram (DSD) is a data model used to describe conceptual data models by providing graphical notations which document entities and their relationships, and the constraints that binds them. The …   Wikipedia

  • ER-Diagram — Das Entity Relationship Modell, kurz ER Modell oder ERM, deutsch Gegenstands Beziehungs Modell, dient dazu, im Rahmen der semantischen Datenmodellierung einen Ausschnitt der realen Welt zu beschreiben. Das ER Modell besteht aus einer Grafik… …   Deutsch Wikipedia

  • Entity-Relationship-Diagram — Das Entity Relationship Modell, kurz ER Modell oder ERM, deutsch Gegenstands Beziehungs Modell, dient dazu, im Rahmen der semantischen Datenmodellierung einen Ausschnitt der realen Welt zu beschreiben. Das ER Modell besteht aus einer Grafik… …   Deutsch Wikipedia

  • Entity-Relationship Diagram — Das Entity Relationship Modell, kurz ER Modell oder ERM, deutsch Gegenstands Beziehungs Modell, dient dazu, im Rahmen der semantischen Datenmodellierung einen Ausschnitt der realen Welt zu beschreiben. Das ER Modell besteht aus einer Grafik… …   Deutsch Wikipedia

  • Entity-relationship model — A sample Entity relationship diagram using Chen s notation In software engineering, an entity relationship model (ERM) is an abstract and conceptual representation of data. Entity relationship modeling is a database modeling method, used to… …   Wikipedia

  • Dallas Love Field — This article is about the airport in Dallas, Texas. For the airport in Prescott, Arizona, see Ernest A. Love Field. For the neighborhood around Love Field, see Love Field, Dallas, Texas (Neighborhood). Dallas Love Field USGS aerial photo as of… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”