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Questions tagged [er-diagram]

Entity Relationship Diagram,also called an entity-relationship model A graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems.

Entity Relationship Diagram,also called an entity-relationship model

A graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems.

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Difference between ER diagram and Class diagram

I have been given a description and need to draw ER diagram and Class diagram for the description. Now I am having issue with understanding the differences between these 2 diagrams. When I draw the diagrams entities of ER diagram becomes classes.…
New Developer
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Tools to generate a database diagram/ER diagram from existing Oracle database?

Looking for tools (windows platform) to genereate ER diagram (or similar) from an existing Oracle database. Any good tools out there that are free to use or low cost?
Kb.
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Differences between a conceptual UML class diagram and an ERD?

If I create a conceptual class diagram such that each class captures 'name' and 'attributes' but not 'operations', have I not basically created what would be otherwise considered an ERD? I'm trying to gain an understanding of what the differences…
Adam
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Generate ER diagram Using Hibernate files

I want to form entity relationship diagram from Hibernate configuration and mapping files.Would you please recommend any tools which does it effectively? Thank you...
Hiren
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Relationship with same entity - ER Diagrams

I'm developing a ER model and i have a trouble. I have a entity called client and it pay for another client (Same entity) It's something like this: client(one,many) --- PAY-->(relationship) --- (one,many)client that this right? I thank those who…
Eduardo B.
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ER Diagram Entity without attribute

I have designed an er-diagram and have an entity without any attributes. I need this entity (Item) to create a many-to-many relationshop but I guess there is a way to make this more efficient and getting rid of the entity without attributes. ER…
user6031489
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Designing SQL database in visio

I want to design a schema of my SQL database in Visio But the default database is Microsoft Access, and some datatypes do not exist there (such as tinyint). How can i change the database type to SQL ? I'm using visio 2007 Thanks!
John Terry
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Entity Relationship diagram for a three-way relationship

I want to create an entity relationship diagram for a three way relationship in the following contrived situation: Each COMPANY has many DEPARTMENTS. An EMPLOYEE can work simultaneously for many DEPARTMENTs. However, an EMPLOYEE can work for only…
Anne Forumer
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Tools to draw ER diagrams (tried visio, smartdraw, but didn't work)

I'd like to draw something like below. http://upload.wikimedia.org/wikipedia/commons/7/72/ER_Diagram_MMORPG.png I've Visio, SmartDraw, MySQL workbench, etc. All of them were missing shapes like double lines, weak entity, identifying relationship…
Firefox
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Java graphic 2D library to draw ER diagrams?

I'm looking for a Java 2D graphics library to draw a E-R Diagram from a MySQL database, anyone know something like that? With a 2D Java library graphic I need to draw entities, relationships, foreign keys, primary keys, and attributes. Optionally,…
chroman
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Entities with a strict 1-2 relationship

I am trying to understand how do we model and define the cardinality of two entities when the relationship is of exact nature. Lets say 1 to 2. For an example, if I have entities Journey and Location. Now each journey has 2 locations, a starting…
ResVict
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What is the "Real" ER Diagram?

I am not that much good at database diagraming. Whenever I am asked to create an ERR Diagram, I use MySQL WorkBench software. However today I ended up in a conclusion when I see different types of ER Diagrams. My diagrams (designed via MySQL…
PeakGen
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Convert EER-Diagram/Generated Schema to ER Diagram

I'm working on a school project that requires the creation of an ER diagram and a database schema that is derived from that diagram. The schema has some very stringent size requirements (no more than x number of tables). I'm running into an issue…
Schmidget
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Using ONLY Entity Relationship Diagram to Query MYSQL Format [BRAIN CHALLENGE]

Normally we query using tables and schema but in my case I have to use Entity Relationship Diagram ONLY to query on a piece of paper in MYSQL Format. These are really making things complicated. I require your help for example this question. …
Zeus
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Representing multiple candidate keys in RM

I have problems in understanding why the following mapping from an ER-diagram to an ERM is correct, or, to be more precise complete. In the given example we have a ternary 1:1:N relationship between a project, a place and persons. Each entity has a…
Marvin
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