entity-attribute-value

I am trying to so something like Database Design for Tagging , except each of my tags are grouped into categories. For example, let's say I have a database about vehicles. Let's say we actually don't know very much about vehicles, so we can't specify the columns all vehicles will have. Therefore we shall "tag" vehicles with information. 1. manufacture: Mercedes model: SLK32 AMG convertible: hardtop 2. manufacture: Ford model: GT90 production phase: prototype 3. manufacture: Mazda model: MX-5 convertible: softtop Now as you can see all cars are tagged with their manufacture and model, but the

Below, I explain a basic design for a database I am working on. As I am not a DB, I am concerned if I am on a good track or a bad one so I wanted to float this on stack for some advice. I was not able to find a similar discussion that fit's my design. In my database, every table is considered an entity. An Entity could be a customer account, a person, a user, a set of employee information, contractor information, a truck, a plane, a product, a support ticket, etc etc. Here are my current entities (Tables)... People Users Accounts AccountUsers Addresses Employee Information Contractor

I want to extract results from EAV (entity-attribute-value) tables, or more specifically entity-metadata tables (think like wordpress wp_posts and wp_postmeta ) as a "nicely formatted relational table", in order to do some sorting and/or filtering . I've found some examples of how to format the results within the query (as opposed to writing 2 queries and joining the results in code), but I would like to know the "most efficient" method for doing so, especially for larger result sets. And when I say "most efficient", I mean for something like the following scenarios: Get all Entities with last

I need to design a Key/value table in my database and I'm looking for guidance on the best way to do this. Basically, I need to be able to associate values to a dynamic set of named properties and apply them to an external key. The operations I need to be able to support are: Apply a key/value pair to a group of items Enumerate all of the currently-active keys Determine all of the items that have a value for a given key Determine all of the items where the value associated with a given key matches some criteria. It seems that the simplest way to do this is to define a table: CREATE TABLE

I am building a software platform for mobile electronic data collection. It should support any type of data. For example, the government might use it for a population survey; a manufacturing company might use it to evaluate plant condition at their factories; a research organizations might use it for clinical trials, e.t.c As such, the software is powered by a database, with standard relational design for the metadata and entity attribute value for the actual data. Client software then reads the metadata and renders the appropriate user interface, complete with rules, validations, skip logic