Simple EAV schema

eav.sql

DROP TABLE IF EXISTS `attributes`;
CREATE TABLE  `attributes` (
  `name` VARCHAR(64) NOT NULL, 
  PRIMARY KEY (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `attr_value_pairs`;
CREATE TABLE `attr_value_pairs` (
  `id` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
  `attr` VARCHAR(64) NOT NULL,
  `value` TEXT NOT NULL,
  PRIMARY KEY (`id`),
  CONSTRAINT `fk_attr`
    FOREIGN KEY (`attr` )
    REFERENCES `attributes` (`name` )
    ON DELETE NO ACTION ON UPDATE NO ACTION,
  UNIQUE KEY `id_attr` ( `id`, `attr`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `targets`;
CREATE TABLE `targets` (
  `id` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
  `email` VARCHAR(128) NOT NULL,
  `attr_value_id` BIGINT(20) UNSIGNED NOT NULL,
  KEY `target_email_key` (`email`),
  UNIQUE KEY `id_email_attr` ( `id`, `email`, `attr_value_id`),
  PRIMARY KEY (`id`),
  CONSTRAINT `fk_attr_value_pair` 
    FOREIGN KEY (`attr_value_id` )
    REFERENCES `attr_value_pairs` (`id` )
    ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;