EAV (Entity, Attribute and Value) confusion ..?

Question

I have some doubt in EAV. As for as I know EAV is should only be used when you are not sure about number of fields in a table which can vary in future. So eav_attribute table holds the attribute's and the values are stored in,

- eav_entity, eav_entity_int (for holding Integer values),
- eav_entity_varchar (for holding Varchar values),
- eav_entity_datetime (for holding Datetime values),
- eav_entity_decimal (for holding Decimal/float values),
- eav_entity_text (for holding text (mysql Text type) values).

I have checked those tables in default magento installed database and my magento projects (as far as i did yet) but, those tables doesn't stored any data. All are empty. Its make me mad.. Where the EAV used exactly..? Can any body explain about this with example please ..?

Answer 1

Correct.

Magento started with this concept but it was too slow, so they decided to have tables for every eav_type on its own.

you find the following tables (maybe I forget some)

• catalog_category_entity_*
• catalog_product_entity_*
• customer_entity_*
• customer_address_entity_*

The basic data are stored in the entity table, e.g. customer_entity

Answer 2

As far as I know these are left is so you can build your own models that use EAV. The standard eav in Magento, Customers, Products etc have their own tables.

For the customer attributes each table starts with customer_entity