Top "Relational-database" questions

A relational database is a database consisting of relation variables (which are also called *relvars*, *R-tables* or just *tables*). The definition, manipulation and integrity rules of relational databases are based on relational operations equivalent to or similar to the Relational Algebra and Calculus.

Algebra Relational sql GROUP BY SORT BY ORDER BY

I wanted to know what is the equivalent in GROUP BY, SORT BY and ORDER BY in algebra relational ?

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Adding constraints in phpMyAdmin

I feel like I'm being stupid, but I can't find anywhere on the phpMyAdmin interface to add constraints to foreign …

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SQL two tables and creating a link table

I have two tables: Employee (ID, Name, Address) and Store(ID,Address) and I would like to record information about …

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What is the difference between MySQL & MySQL2 considering NodeJS

So I have read the following post" What the difference between mysql and mysql2 gem So far I have only …

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NULL permitted in Primary Key - why and in which DBMS?

Further to my question "Why to use ´not null primary key´ in TSQL?"... As I understood from other discussions, some …

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Modeling Product Variants

I've been trying to model product variants and thought that I might need to use EAV. I might have been …

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Can one make a relational database using MongoDB?

I am going to make a student management system using MongoDB. I will have one table for students and another …

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Lossless Join Property

Can someone please explain to me what is meant by the lossless join property in a relation schema? Is it …

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Look-up vs relationship Microsoft Access

I'm developing a Microsoft Access 2013 based information system. One of the client's demands was to simplify the data entry process …

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When I should use one to one relationship?

Sorry for that noob question but is there any real needs to use one-to-one relationship with tables in your database? …

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