ER-Diagram Symbols

Above you see the atomic building blocks of the ER-Diagram: Entity Attribute Relation Carninalities (Crow’s feet notation) one, zero-or-one, zero-or-many, one-or-many, many. From Requrements to Deployment ER-Diagram This ER-Diagram is inspired by some of the tables in his sample database   Database Implementation Here are Ben Forta’s tables in PhpMyAdmin “design viewW. During implementation you… Continue reading ER-Diagram Symbols

Adminer – a lightweight alternative to PhpMyAdmin

PhpMyAdmin is powerfull but the GUI is messy. Adminer is a lightweight alternative. You have to download the files and place them in your folder. # sudo apt-get isntall adminer # sudo ln -s /usr/share/adminer/ adminer The first line will install the files. They are saved in /usr/share/adminer. Therefore we need a symbolic link to… Continue reading Adminer – a lightweight alternative to PhpMyAdmin

SQL: Many-to-Many and One-to-Many

Here’s a short tutorial on how to solve some basic SQL cardinalities. First have a look at the ER-diagram for the database and the resulting tables in PhpMyAdmin. Many-to-Many Many to many cardinalities may be solved like this: SELECT cake, who FROM cakes, costumers, likes WHERE costumers.costumers_id = likes.costumers_id AND cakes.cakes_id = likes.cakes_id Note that… Continue reading SQL: Many-to-Many and One-to-Many