From f3559783856e49268b099699f0c00968be1a2628 Mon Sep 17 00:00:00 2001 From: Ryan Date: Wed, 14 Jun 2023 14:35:28 +0800 Subject: [PATCH] Auto saved by Logseq --- pages/总复习2023t1.md | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md index d15e828..961838f 100644 --- a/pages/总复习2023t1.md +++ b/pages/总复习2023t1.md @@ -962,14 +962,17 @@ - Most useful additional concept of EER model: specialization/generalization. - Superclass :-> An entity type that includes one or more distinct + id:: 64895f2f-b868-46ec-9d80-7079eaf3197d subgroupings of its occurrences. - - Superclass/subclass relationship is one-to-one - (1:1). - - Superclass may contain overlapping or distinct - subclasses. - • Not all members of a superclass need be a - member of a subclass. + - Superclass/subclass relationship is {{c1 one-to-one + id:: 64895f70-57e0-4023-9c32-34f1380aba1e + (1:1).}} #flashcard + - Superclass may contain overlapping or distinct + subclasses. + - Not all members of a superclass need be a + member of a subclass. - Subclass :-> A distinct subgrouping of occurrences of an entity + id:: 64895f39-d886-436b-9afe-ba75d37c8b45 type. - LATER designing ER diagram - DONE Block 3