# Practice Problems - Write Code¶

Now, let’s spend 15 minutes to practice what we just learned!

Please do not refer back to the previous page or outside resources.

You can stop working on a problem after you worked on it for about three minutes without solving it.

## Problems¶

In the grades table:

Please write a SELECT statement to retrieve the student_id, test_name, and english of all entries whose english is lower than 60 and math is higher than 90.

note: When you run the code, there will be several execution results. Please only refer to the unittest and the last execution result for debugging purposes.

In the grades table:

A student completed an extra assignment and got some additional points.

Please write an UPDATE statement to change the entry whose student_id is 1, and set their math score for final test_name to 90.

note: When you run the code, there will be several execution results. Please only refer to the unittest and the last execution result for debugging purposes.

In the grades table:

The instructors decided to add some points to all students as one test was too difficult.

Please write an UPDATE statement to change all entries whose test_name is midterm, and add 10 points to their english score.

note: When you run the code, there will be several execution results. Please only refer to the unittest and the last execution result for debugging purposes.

Aside from the grades table:

We also have a students table:

Now we want to match the student name to their math grades.

Please write a statement using SELECT and JOIN to: select the test_name and math from the grades table and name from the students table, where the student_id in the grades table is the same as the id in the students table.

note: When you run the code, there will be several execution results. Please only refer to the unittest and the last execution result for debugging purposes.

Aside from the grades table:

We also have a tests table:

Now we want to add the date information to the grades to see when the students took the tests.

Please write a statement using SELECT and JOIN to: select the date and name from the tests table and student_id from the grades table, where the test_name in the grades table is the same as the name in the tests table.

note: When you run the code, there will be several execution results. Please only refer to the unittest and the last execution result for debugging purposes.

## What to do next¶

Click on the following link to go to the post test: Post Test