How to handle cross-table queries in SQLite?

Cross-table queries in SQLite can be achieved by using JOIN statements. SQLite supports different types of JOIN operations such as INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN. Users can select the appropriate JOIN type based on their specific needs for cross-table queries.

Here is a simple example demonstrating how to perform a cross-table query in SQLite.

Assuming there are two tables, one for students and one for courses, that are connected by student IDs. We need to query the names of students and the names of the courses they are taking.

SELECT students.name, courses.course_name
FROM students
INNER JOIN courses ON students.student_id = courses.student_id;

In the example above, we used INNER JOIN to connect the student table and the course table, linking them by student ID. The query results will return the student’s name and the name of the course they are enrolled in.

Apart from INNER JOIN, other types of JOIN such as LEFT JOIN, RIGHT JOIN, and FULL JOIN can also be used for querying across tables. The specific choice of JOIN depends on the query requirements and data relationships.

Leave a Reply 0

Your email address will not be published. Required fields are marked *


广告
Closing in 10 seconds
bannerAds