Hello All,
I have a question regarding the creation of the tables in the database. When we draw entity relationship diagram and figure out the entities and its attributes, Do these entities eventually become the tables in our database?
In general, if the business entities are modeled correctly in a logical model and assuming the database will be normalized, most of the entities in the logical model will eventually become tables in the database and the attributes for a given entity become columns in the respective table
However, in many cases the DB architect or the development team might decide to de-normalize the data in the database (for performance/technical reasons). In these cases there could be multiple tables in the database which contain information about a business entity.
- Adrian
Thanks Adrian,
Can you also provide me any good links to learn more about Entity relationship diagrams, i mean how to draw the multiplicities/cardinalities between entities.
Here are a couple of resources on creating E-R diagrams:
Data Modeling: Finding the Perfect Fit
Logical Data Structures (LDSs) - Getting started
Introduction to Data Modeling
Just Enough Structured Analysis - see Chapter 12
Depending on what tools you have at your disposal, using a class diagram to model data is also an option - here are some articles on class diagrams.
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