UPDATE with subquery preview in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to update the salary of employees to 50000 where their department is 'Sales'.

SQL

UPDATE employees SET salary = [1] WHERE department = 'Sales';

Drag options to blanks, or click blank then click option'

ANULL

B50000

Csalary + 50000

D'50000'

Attempts:

3 left

💡 Hint

Common Mistakes

Putting 50000 in quotes, which makes it a string.

Using salary + 50000 which adds instead of setting.

The salary should be set to the number 50000 without quotes because salary is a numeric column.

2fill in blank

medium

Complete the code to update the salary of employees to the average salary of their department.

SQL

UPDATE employees SET salary = (SELECT AVG(salary) FROM employees WHERE department = [1]);

Drag options to blanks, or click blank then click option'

Adepartment

Bsalary

C'department'

D'Sales'

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around department, making it a string instead of a column.

Using salary instead of department.

The subquery compares the department column of the outer query with the department column inside the subquery, so no quotes are needed.

3fill in blank

hard

Fix the error in the code to update employees' salary to the maximum salary in their department.

SQL

UPDATE employees SET salary = (SELECT MAX(salary) FROM employees WHERE department = [1]);

Drag options to blanks, or click blank then click option'

Adepartment

B'Sales'

C'department'

Dsalary

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around department.

Using a fixed string like 'Sales' instead of the column.

The subquery must compare the department column of the outer query to the inner query's department column without quotes.

4fill in blank

hard

Fill both blanks to update employees' bonus to 10% of their salary where their department is 'Sales'.

SQL

UPDATE employees SET bonus = salary * [1] WHERE department = [2];

Drag options to blanks, or click blank then click option'

A0.1

B'Sales'

Cdepartment

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using 10 instead of 0.1 for percentage.

Not quoting the department string.

The bonus is 10% so 0.1 is used. The department is a string, so it needs quotes.

5fill in blank

hard

Fill all three blanks to update employees' salary to the average salary of their department only if their current salary is below that average.

SQL

UPDATE employees SET salary = (SELECT AVG(salary) FROM employees WHERE department = [1]) WHERE salary < (SELECT AVG(salary) FROM employees WHERE department = [2]) AND department = [3];

Drag options to blanks, or click blank then click option'

Adepartment

B'HR'

C'Sales'

Dsalary

Attempts:

3 left

💡 Hint

Common Mistakes

Quoting the department column in subqueries.

Not quoting the department string in the WHERE clause.

The subqueries compare the department column, so use the column name without quotes. The final department filter is a string, so it needs quotes.