Easy
Count rows which meet a condition I
Count the number of students in the students table whose first name contains the letter 'u' (upper-case or lower-case).
SCHEMA
students
+------------+------------+-----------+-----+------------+
| student_id | first_name | last_name | age | class_code |
+------------+------------+-----------+-----+------------+
| 1 | Mike | Chaplin | 12 | 7A |
| 2 | Emily | Jackson | 12 | 7A |
| 3 | Robert | Jackson | 12 | 7A |
| ... | ... | ... | ... | ... |
+------------+------------+-----------+-----+------------+
EXPECTED OUTPUT
+------------------------------+
| num_first_names_containing_u |
+------------------------------+
| 60 |
+------------------------------+
Use the WHERE keyword to filter the students table.
Use the LOWER() keyword to convert all first names to lowercase, and then use a regex pattern like '%u%' to match first names which contain a 'u'.
SELECT
COUNT(*) AS num_first_names_containing_u
FROM students
WHERE LOWER(first_name) LIKE '%u%'