SQL Programming Intermediate Quiz 1

1. What does an INNER JOIN do?

2. Which SQL clause is used to group rows that have the same values?

3. How do you count the number of unique values in column "city" in table "clients"?

4. Which function returns the data type of a column in most SQL dialects?

5. How do you select the first 10 rows from a table?

6. Which statement adds a PRIMARY KEY to a table?

7. How do you find the average salary from "employees"?

8. Which SQL keyword is used to prevent NULL values in a column?

9. How do you select all employees hired after 2020-01-01?

10. Which SQL clause is used to filter groups after GROUP BY?