Question

Consider a relation that describes an employee including the province where the employee was born. Suppose the only key is employeeId and we have the attributes: name, birthDate, birthProvince, currentPopulation.

Short answer

The 'employee' relation uses 'employeeId' as the unique key to represent each record. The attributes within this relation include 'name', 'birthDate', 'birthProvince', and 'currentPopulation', describing personal, birth, and demographic details about each employee.

Step-by-step solution

Identify the Key

In the described relation, the only key given is 'employeeId'. This is the attribute that uniquely identifies each record in the database.

Recognize the Attributes

The relation consists of four attributes: 'name', 'birthDate', 'birthProvince', 'currentPopulation'. These provide information about each employee.

Understand the Relation

The relation 'employee' reflects the connection between an employee's identification number, their personal details like name and birth details, as well as the data involving the current population of their birth province.

Key concepts

Relational Databases

Relational databases are a collection of organized data, where the information is stored in tables. Each table, also known as a relation, holds data related to a specific entity, such as employees or products. These tables are linked to one another through relationships. This setup allows for efficient data retrieval and management.
In a relational database, data is structured in rows and columns, much like a spreadsheet. Each row, or record, within a table represents a unique instance of the entity. The intersection of a row and a column is called a field, which contains actual values for an attribute of the entity, like an employee's name or birthdate.

• Tables are fundamental components in a relational database.
• Data integrity and consistency are maintained through keys and rules.
• Queries help users extract and manipulate the data stored in the tables.

Relational databases use a structured query language (SQL) to interact with the data. This language allows for operations such as querying records, updating entries, and defining data structures. It is vital for maintaining organized and reliable datasets that can support complex search and management tasks.

Primary Key

A primary key is a crucial concept in database design. It is an attribute or a set of attributes that uniquely identifies each record within a table. The primary key ensures that no two rows in a table can have the same primary key value.
In our exercise about employee records, the 'employeeId' plays the role of the primary key. This unique identifier distinguishes each employee's record from another, preventing duplication and ensuring data integrity.

• Every table needs a primary key for unique identification.
• Primary keys enforce entity integrity by ensuring no duplicate records.
• Choosing a primary key is a fundamental part of database design.

Understanding primary keys helps in designing databases that are not only efficient but also resilient to errors such as data duplication or inconsistency. They are an essential element that facilitates the establishment of relationships between different tables in a relational database.

Employee Records

Employee records in a database context refer to the collection of data concerning each employee, stored in a designated table. These records hold essential details about each individual that the organization needs to manage effectively.
In the exercise, several attributes like 'name', 'birthDate', 'birthProvince', and 'currentPopulation' are mentioned. These attributes provide insights into various aspects of an employee's background and personal data.

• Name: An essential identifier, but not unique.
• BirthDate: Indicates the employee's date of birth.
• BirthProvince: Reveals the original location linked to cultural or demographic data.
• CurrentPopulation: While unusual for a personal record, reflects demographic info relevant to the birth province.

Storing employee records correctly helps organizations manage human resources efficiently. Organizing and accessing these details through a well-constructed relational database ensures that the information remains easily accessible and manageable, supporting various administrative processes.