Top "Relational-model" questions

Unique key with NULLs

This question requires some hypothetical background. Let's consider an employee table that has columns name, date_of_birth, title, salary, …

mysql database null relational-model

How to generate Relational Model from UML Class Model?

Does anyone know an application (Enterprise Architect, ...) that allows mapping from UML Class Model to Database Relational Model automatically? How? …

uml relational-database enterprise-architect relational-model

Procedurally transform subquery into join

Is there a generalized procedure or algorithm for transforming a SQL subquery into a join, or vice versa? That is, …

sql algorithm join subquery relational-model