I gave you the basics. Good luck.

Does Table1 (email, pass, gender, dob) have a foreign key constraint on CompanyTable? If so, let the database handle the foreign key validation and have the web application check for errors.
...

SELECT h.name
FROM Human h, Attribute a, Human_Attribute ha
WHERE h.human_id = ha.human_id and a.attribute_id = ha.attribute_id and a.attribute_id in (list)

Glad to hear.

Good luck with your project.

Why is it not ip_from and ip_to = ?

I have not dealt with using a composite primary key and then adding in >= or <=. I have always set them equal.

While it may not be the use scenerio you are...

Sadly, no. You cannot link Inno and MyISAM and maintain foreign key constraints. I found this one out the hard way as well and is causing me a slight headache.

I did convert the MyISAM to InnoDB...

What caused the force?

From what I have been able to gather over the last few days, InnoDB is more robust, yet more resource intensive.

This link is a bit dated, but shows what each [MYSQL...