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Database - continued...

Sorry to get technical on you like that, without any warning, so to speak, I'll try to be more careful next time.

But since you are here, we might as well go on, because it is kind of interesting, in an abstract, obscure, arcane way.  Well, ok, maybe I'm pushing it, just a little.

Anyway, an Entity  Relationship Diagram (or ERD for short), is a way of visually describing how a database works.  Not that it explains everything, but it does explain quite a bit.  Because a database works by being able to link separate database parts together to combine data to make information.

The database parts are tables of data, similar to, but not the same as an Excel table. In the diagram below, 4 tables are represented:  Customers, Orders, Order Details and Products.  When a sales rep signs on a new  customer, that data goes into the Customers table.  And when that customer (or any other customer) places an order, that order data goes into the Orders table and the Order Details table.  

And when  new products are added to the product catalog, that data goes into the Products table.

Getting back to the diagram below, it shows the pieces of data in each table, called attributes (or data elements).  Each table is similar to a separate file and each group of data elements for each row of the table is similar to a record in the file. The ability of the database to link together the separate, but corresponding records from each table is what gives a database system its power.

The database system uses a language called SQL to allow techies to combine data to make information.  SQL is also called Sequel (and often pronounced that way, on purpose) and actually is an acronym for Structured Query Language.  SQL is easy to learn at first, but gets complex quickly.

Protometrix Systems is proficient at analyzing, designing and building databases and systems, from the simple to the complex.

And we would be glad to help you with your system, too!

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ERD (Entity Relationship Diagram)