Joins in SQL: interview exercises

Joins in SQL: 7 test-checked interview exercises (INNER JOIN, LEFT JOIN keeps everyone), each beside a worked example, with tests as you go. Free.

1. INNER JOIN
2. LEFT JOIN keeps everyone
3. Join, then aggregate
4. Three tables
5. Join a table to itself
6. Rows with no match
7. Totals that include empty groups

Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.

More SQL topics

• Select & Filter
• Aggregation
• Subqueries & CTEs
• Window Functions
• Strings, Dates & CASE
• Modifying Data
• Schema Design

All SQL exercises · Other languages and frameworks