Background:
\n It is insane to build a table describing every attribute for huge a lot of entities, because there are many spareness in it.<\/p>\n
Definition:
\n 1. entity: the things to be described
\n 2. attribute: ways or data to desribe the entity
\n 3. value: the value of attribute
\n then:
\n 1. a row is a fact
\n 2. attribute and value pair is a fact describing an entity<\/p>\n
In detail:
\n the entity is also like a array, which includes, in the clinical example, name and brief descpriton.
\n the attribute is cited from attribute definition table as a foreign key.<\/p>\n","protected":false},"excerpt":{"rendered":"
Background: It is insane to build a table describing every attribute for huge a lot of entities, because there are many spareness in it. Definition: 1. entity: the things to be described 2. attribute: ways or data to desribe the entity 3. value: the value of attribute then: 1. a row is a fact 2. … Continue reading “EAV model”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-52","post","type-post","status-publish","format-standard","hentry","category-it"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/posts\/52","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=52"}],"version-history":[{"count":2,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/posts\/52\/revisions"}],"predecessor-version":[{"id":54,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=\/wp\/v2\/posts\/52\/revisions\/54"}],"wp:attachment":[{"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=52"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=52"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kiyoguan.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}