BEFORE trigger execution in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a BEFORE INSERT trigger that sets the new salary to 5000.

SQL

CREATE TRIGGER set_salary_before_insert BEFORE INSERT ON employees FOR EACH ROW BEGIN SET NEW.salary = [1]; END;

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

A5000

BNULL

Csalary

DDEFAULT

Attempts:

3 left

💡 Hint

Common Mistakes

Using OLD.salary instead of NEW.salary

Assigning NULL which removes the salary

Using DEFAULT keyword incorrectly

The trigger sets the NEW.salary value to 5000 before inserting the row.

2fill in blank

medium

Complete the code to create a BEFORE UPDATE trigger that prevents salary from being set below 3000.

SQL

CREATE TRIGGER check_salary_before_update BEFORE UPDATE ON employees FOR EACH ROW BEGIN IF NEW.salary < [1] THEN SET NEW.salary = [2]; END IF; END;

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

A5000

B3000

C1000

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using OLD.salary instead of NEW.salary

Setting salary to a value higher than the minimum

Using incorrect comparison operators

The trigger checks if the new salary is less than 3000 and sets it to 3000 if true.

3fill in blank

hard

Fix the error in the BEFORE INSERT trigger that tries to modify OLD values.

SQL

CREATE TRIGGER fix_trigger BEFORE INSERT ON employees FOR EACH ROW BEGIN SET [1].salary = 4000; END;

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

Asalary

BOLD

Cemployees

DNEW

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to set OLD values in an INSERT trigger

Using table name instead of NEW or OLD

Assigning values directly to column names

In a BEFORE INSERT trigger, only NEW can be modified. OLD is not available.

4fill in blank

hard

Fill both blanks to create a BEFORE UPDATE trigger that changes the new name to uppercase.

SQL

CREATE TRIGGER uppercase_name_before_update BEFORE UPDATE ON employees FOR EACH ROW BEGIN SET NEW.name = [1](NEW.name); END;

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

ATRIM

BLOWER

CUPPER

DLENGTH

Attempts:

3 left

💡 Hint

Common Mistakes

Using LOWER instead of UPPER

Using LENGTH which returns a number

Using TRIM which removes spaces

The UPPER function converts the new name to uppercase before update.

5fill in blank

hard

Fill all three blanks to create a BEFORE INSERT trigger that sets new salary to 6000 if NULL or less than 6000.

SQL

CREATE TRIGGER set_min_salary_before_insert BEFORE INSERT ON employees FOR EACH ROW BEGIN IF NEW.salary IS [1] OR NEW.salary [2] [3] THEN SET NEW.salary = 6000; END IF; END;

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

ANULL

B<

C6000

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using IS NOT NULL instead of IS NULL

Using > instead of < for comparison

Comparing to wrong salary value

The trigger checks if NEW.salary is NULL or less than 6000, then sets it to 6000.