Relational Database
Relational database is a type of database that organizes data in tables with predefined relationships. These tables consist of rows (records) and columns (attributes).
Below is a visual representation of what a relational database could look like:
| Index | EmployeeId | FirstName | LastName | Department |
|---|---|---|---|---|
| 0 | 123456 | John | Doe | User Experience (UX) |
| 1 | 789012 | Jane | Doe | NA |
The row is a record which contains all the attributes of a specific piece of data. For example, the 0th row is the John Doe’s record of attributes as an employee. Each column is an attribute that an employee or record may have such as an employee ID that is a six digit number. If one of the attributes for a column is blank, usually there are some delimiters, such as “NA”, that indicate that an attribute is not stored.
There can be relationships between tables through common attributes, such as creating a table that presents all the employee IDs of the employees in the User Experience (UX) department. In relational databases, data integrity is enforced through constraints like keys and uniqueness. For example, the EmployeeId is unique to each record.
Relational databases ensure ACID transactions, which ensure reliability and consistency of the data. Relational databases also normalize the data which eliminates redundancy and improves data integrity.
Examples of widely used relational databases are MySQL, Oracle, SQL Server, PostgreSQL, and SQLite. DigitalOcean offers several types of managed databases.
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