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  Techopedia explains Relational Database Design (RDD) Relational databases differ from other databases in their approach to organizing data and performing transactions. In an RDD, the data are organized into tables and all types of data access are carried out via controlled transactions. Relational database design satisfies the ACID (atomicity, consistency, integrity and durability) properties required from a database design. Relational database design mandates the use of a database server in applications for dealing with data management problems. The four stages of an RDD are as follows: Relations and attributes: The various tables and attributes related to each table are identified. The tables represent entities, and the attributes represent the properties of the respective entities. Primary keys: The attribute or set of attributes that help in uniquely identifying a record is identified and assigned as the primary key Relationships: The relationships between the various tables ...

  Learn SQL: Types of relations One of the most important things in databases is to understand the types of relations in the databases. That stands for both – a process of designing a database model as well as when you’re analyzing your data. Understanding these relations is somehow natural and not so complex but is still essential in the database theory (and practice). Data model In the previous article, Learn SQL: SQL Scripts, we’ve extended the data model we’ve used so far by adding a few new tables and filling them with the data.  “Very nice. I like.” . That is the model in the picture below: While the model itself has only 6 tables (real-life models could have hundreds of tables), it contains the most common rules we’ll meet in many other models as well. This also stands for types of relations between tables. Without much effort, you can easily notice that each table is connected/related to another table with exactly one line ( foreign key ). The  primary key ...