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copied!<p>If this is what you're describing:</p> <pre><code> Entity ^ | EntityPropertyValue | | Property<---- PropertyValue ^ | | | --------------------- </code></pre> <p>Where <code>Property</code> defines the various properties that can be applied to a given <code>Entity</code>, <code>PropertyValue</code> defines the values that are valid for a given <code>Property</code>, and <code>EntityPropertyValue</code> defines the value for a given property for a given <code>Entity</code>, then what you have is pretty much exactly EAV (just substitute the word <code>Attribute</code> for <code>Property</code> and you <em>will</em> have exactly EAV).</p> <p>There's nothing inherently wrong with this architecture, and there are certainly some circumstances where it's a valid (and possibly the <em>only</em> valid) choice. Your circumstance does sound like it's a good candidate for EAV.</p> <p>The trouble, as you've discovered, is that it can make querying difficult, especially when you're going to allow the user to specify multiple values for a given property. This will make constructing your result set difficult, as you're going to have to account for potential cartesian products. I can't give you any further advice without seeing an actual query that you're having trouble with (feel free to edit your question and post a comment on my answer; I'll revise it and add some advice if you do), but I can tell you that simply having a "myriad of tables" is not necessarily bad, and, in fact, sounds like the correct design choice given your parameters.</p>

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