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Crow Feet notation and identifying -vs- non-identifying relationships

Is it possible to distinguish between identifying and non-identifying relationships using the Crow Feet notation? Case in point: In table Book, part of the book's Primary Key is a FK to the Author ...
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181 views

Generating an ER Diagram from SQL CREATE TABLE statements

As I can't find any ER diagram feature built in with Apex, I want to create one with the SQL statements I executed in order to set up the tables in my Apex Workbench. I found schemaSpy, which is ...
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1answer
89 views

How much the decision to use ternary or binary relationship influences the accuracy of the model with regards to a given business model?

The question title is very long, so here's a little bit of context to (try to) make it clear. I asked a question regarding ternary relationship. The question was Ternary relationship: what's the ...
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1answer
134 views

Ternary relationship: what's the difference between having single table and having multiple tables?

Consider the following ternary relationship: Suppose that all entities have only two attributes (PK and Name). Here are the tables I derived (5 tables): Sector ------------------------- ...
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1answer
105 views

Conversion of simple ERD to Table: is the solution below any good?

Consider the following ERD: Suppose that all entities only have two attributes: a PK plus a name/number. I want to convert that ERD to tables. Is it needed 4 tables (1 for each relationship ...
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1answer
199 views

MySQL Workbench EER Diagram and ENUM data type

I am creating EER model diagram using MySQL Workbench (version : 5.2.47) The version for MySQL, I am using is 5.5.35-0ubuntu0.13.10.2. I have created a schema with 'Default Collation' set to 'utf8 - ...
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1answer
60 views

Modeling a db that has products: What are the good practices/solutions? How to treat grammar variations in the words?

The problem is: A Company belongs to a sector. A Company produces products. A Sector contains products. A Product belongs to sectors. Three entities: Company, Sector and Product. And it's a ...
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1answer
62 views

What are the bad design points in the following (simple) Entity-Relationship Diagram?

The objective is to design a Entity-Relationship Model for a company that has addresses, telephones, e-mails and representants. Here's the list of the constraints: a company has one or more ...
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1answer
72 views

Database Normalization: A Case Of The NULLs [duplicate]

I'm trying to learn about proper database management and am having a hard time with designing a database that doesn't rely on NULLs. If you think I'm crazy for embarking on this, it is because of SQL ...
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104 views

Which tool to use to generate an ER Diagram that will allow navigation between tables

DB= Mysql 5.X , OSX/Windows I have a DB with over 400 tables. I want to use a tool to reverse engineer the db to an ER diagram that will allow me to navigate between tables. So for example, when I'm ...
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0answers
37 views

MySQL Workbench Forward Engineer from only the current diagram

I want to create a test database from a huge schema in MySQL, but when I try to do Forward Engineer from a Diagram with about 6 tables, it try to create all the tables, views and routines groups that ...
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20 views

how to assign multiple/single role between two entities

I have user and school table with roles as student,teacher,schooladmin and schoolheadadmin. If user is student then he/she can not have any other role in same school but if user is teacher then s/he ...
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1answer
88 views

SQL Server 2008 Script Changes from Database Diagram

I have a database diagram which I have made several changes to using SSMS, however instead of committing the changes I want to generate a SQL script to apply them instead. Is there a simple way to do ...
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1answer
291 views

Automatically create ER diagram from database schema

I have a database with 193 tables and I need to create an ER diagram from them. There are no formal relationships between the tables with respect to FKs. The relationships are mapped with 1-* tables. ...
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2answers
118 views

Can relationships have relationships?

I have the following requirements (as part of a larger system). In the database, I need to maintain a list of parts, suppliers who sell those parts. Many suppliers can sell the same part and each ...
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0answers
212 views

Number of ISA relationship triangles in an Entity Relationship Diagram

The following two diagrams are nearly identical. However, in one, there are two ISA triangles from the Entity "Movie" and in the other there is just one. What is the difference in meaning?
2
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1answer
108 views

ER relation with unique key

I've a problem about my ER diagram. Assume that I want to draw a diagram with student, member and team. Here is my specs: A student does not have to be a member of any team. A student could be a ...
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0answers
76 views

Need advice on this EER Diagram

This db will work with a CakePhp app and need advice about design. Is it good idea to put orders on center or should I put clients on center? Clients has orders and an order record can only have one ...
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2answers
464 views

How can I get a list of tables contained in a database diagram?

I need to get a list of the tables contained in a diagram in SQL Server. How can I do it using an SQL script? I don't need a list of tables in the database, but the list of tables contained in a ...