Could it be such things as tables? Or wouldn't it also can consist of constraints, saved methods, packages, etc.?
I have looked round the internet, but finding elementary solutions to elementary questions may also be just a little difficult.
That's a significant general question!
Essentially, all sorts the database system itself offers, like Number, VARCHAR etc., or the programming language of preference offers (int, string etc.) could be considered "atomic" data(base) types.
Something that you - according to your program's or business' needs - build from that, business objects and so on, are organizations.
Tables, constraints and so on are database-internal objects required to store and retrieve data, but individuals are general not considered "organizations". The information saved inside your tables, when retrieved and changed into an item, that then is definitely an entity.
Within the entity relationship world an entity is one thing that may exist individually and thus there's frequently a 1-to-one relationship between organizations and database tables. However, this mapping is definitely an implementation decision: For instance, an ER diagram could have three organizations: Triangular, Square and Circle which may potentially be modelled like a single table: Shape.
Also observe that some database tables may represent associations between organizations.
it type of is dependent the way you consider it and just how you model your condition domain. more often than not whenever you learn about organizations, they're database tables (one or many) planned onto object classes. Therefore it is no entity until it has been queried for and converted into a category instance.
however, it is dependent in your modeling methodology, and you will find multiple :-)
We'd have to know some context. One factor people sometimes do when examining data in prepartion for creating a database would be to create an Entity Realtionship Diagram, where you stand thinking about what data products you're controlling as well as their associations.
I question if that is the context you mean?
If that's the case possibly a read of the article would enable you to get began?
This thread is demomnstrating one good reason why it is not easy to locate "elementary solutions to elementary questions". Certain words happen to be utilized by different programming paradigms to mean various things (try asking a lot of OO developers what's the distinction between a category as well as an Object sometime).
Here's my undertake it.
When i first discovered Entity like a modelling term in SSADM (request your father). For the reason that context an Entity can be used to model may well clump of datas throughout the needs gathering / analysis phase. The associations between organizations were modelled while using Entity Relationship diagrams, and also the profile of the Enity was modelled using Entity Existence Histories. ELH diagrams were very helpful in COBOL systems but absolutely horrible in relational databases. ERDs however continue being helpful even today.
Throughout the look and implementation phases the Organizations get resolved into database tables, objects or records inside a COBOL input file. Throughout that process may well entity could get split across multiple tables, or several organizations could get squidged right into a single table, or there might be a 1-to-one mapping. Sometimes an entity is resolved away entirely or remains on like a view or perhaps a saved procedure.
This appears useful: http://en.wikipedia.org/wiki/Entity-relationship%5Fmodel
Inside a database an entity is really a table. The table signifies whatever real life concept you are attempting to model (person, transaction, event).
Contraints can signifies associations between organizations. These could be foreign secrets. Additionally they enforce rules like first_title cannot be blank (null). A transaction should have 1 or even more products. A celebration should have to start dating ? time.
Saved Methods / Packages / Triggers could handle more complicated associations and/or they are able to handle business rules, just is dependent on which it's doing.