Need a MySQL query for selecting from a table storing key value pairs

Question

I need to store few items and its properties in form of a key value pairs in the database (mySQL). I am planning to do it as following.

I\'ll use two tables it

Answer 1

Here is an example query:

SELECT
  itemName
FROM
  items i,
JOIN
  item_properties effect
  ON i.itemId = effect.itemId AND effect.property = 'effect'
JOIN
  item_properties consumption
  ON i.itemId = consumption.itemId AND consumption.property = 'consumption'

WHERE effect.value = 'cooling' AND consumption.value = 'efficient';

I'll leave the oR query as something you can try yourself. It's simply adding more tables and using OR instead of AND in the WHERE.