SQL Joins: Combine Rows Across Multiple Tables

Working with data in modern relational databases requires more than just querying single tables. To extract meaningful business insights, you must understand how to link separate datasets through relational connections. This text-based course guides you from foundational database concepts to writing clear, efficient multi-table queries. You will start by understanding database relationships, primary keys, and foreign keys before writing your first relational query. By the end of this course, you will confidently construct queries that merge, filter, and summarize data from multiple sources. What you'll learn: Understand core database relationships and key terminology; Write inner joins to combine matching data across tables; Use left, right, and full outer joins to handle missing or unmatched records; Combine aggregation functions with joins to calculate enrollment metrics and summaries; Practice writing clean, readable SQL queries that follow modern formatting standards. We begin with essential definitions and relational design principles, then step through practical scenarios involving student, course, and enrollment tables. This course is designed for beginners who have a basic grasp of simple select statements but want to master combining data. Start reading today to unlock the full potential of relational databases.