relaatiotaulun

Relaatiotaulun, often translated as relational table, is a fundamental concept in the relational model of databases. It represents a data structure that organizes data into rows and columns. Each row, also known as a tuple or record, represents a single instance of an entity, while each column, also known as an attribute or field, represents a specific characteristic or property of that entity.

The structure of a relational table is defined by its schema, which specifies the names of the columns and the data types they can hold. This ensures data consistency and integrity. For example, a table named "Customers" might have columns like "CustomerID" (an integer), "FirstName" (text), "LastName" (text), and "Email" (text). Each row in this table would then represent a unique customer with their corresponding details.

Relationships between different relational tables are established through keys. A primary key is a column or set of columns that uniquely identifies each row within a table. A foreign key is a column in one table that refers to the primary key in another table, thus creating a link or relationship between the two tables. This allows for complex data to be stored and retrieved efficiently by joining related tables. The relational model, with its reliance on tables, is the basis for most modern database systems.