Properties2
| Type | Concept |
| Note created | Feb 17, 2025 |
A relational database is based on the relational model of data, proposed by E. F. Codd in 1970. A digital system that uses such relational model is called a relational database management system or RDBMS. Most RDBMS use the SQL language for querying and maintaining the system.
The relational model can be summarized with some basic concepts:
- Data must be tabular and is organized in tables or relations.
- Tables have columns for data attributes and each of the rows represent a record that must define values for such attributes.
- The data model must define relationships between the tables.
- Relations can define keys: a primary key is used to uniquely identify each record of a table, and a foreign key is used to define the relationships between to tables.
- To query, modify or delete these records and tables you can use SQL, which defines operators based on relational calculus and algebra.