Explicit Join
Explicit joins use the JOIN keyword to specify the join condition directly in the ON clause. This approach provides better readability and clarity, as the relationship between tables is explicitly stated in the query. Types of explicit joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
Consider the following database,
database
Example 1
SELECT employees.employee_name, departments.department_name
FROM employees
JOIN departments ON employees.department_id = departments.department_id;
Output:
Example-1 output
Explanation: This query performs an inner join between the employees and departments tables based on the common department_id column. It returns the employee_name and department_name for each employee along with their corresponding department.
Example 2
SELECT employees.employee_name, departments.department_name
FROM employees
LEFT JOIN departments ON employees.department_id = departments.department_id;
Output:
Example-2 output
Explanation: This query performs a left join between the employees and departments tables, ensuring that all rows from the employees table are included in the result set. If an employee does not belong to any department, the corresponding department_name will be NULL.
Explicit vs Implicit SQL Server Joins
SQL Server is a widely used relational database management system (RDBMS) that provides a robust and scalable platform for managing and organizing data. MySQL is an open-source software developed by Oracle Corporation, that provides features for creating, modifying, and querying databases. It utilizes Structured Query Language (SQL) to interact with databases, making it a popular choice for web applications and various software systems. MySQL’s versatility, reliability, and ease of use make it a preferred solution for developers and organizations seeking efficient data management capabilities.
In this article, you will learn about, Explicit vs implicit SQL Server joins.