Standard comparison operators in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select rows where age is equal to 30.

PostgreSQL

SELECT * FROM users WHERE age [1] 30;

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

A<

B!=

C=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '=' will select rows where age is not 30.

The equal sign = is used to compare if two values are the same.

2fill in blank

medium

Complete the code to select rows where salary is greater than 50000.

PostgreSQL

SELECT * FROM employees WHERE salary [1] 50000;

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

A>

B<

C=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' will select salaries less than 50000, which is incorrect here.

The greater than operator > selects values larger than the given number.

3fill in blank

hard

Fix the error in the code to select rows where score is not equal to 100.

PostgreSQL

SELECT * FROM results WHERE score [1] 100;

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

A>

B=

C<

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' will select rows where score equals 100, which is wrong here.

The not equal operator != selects rows where the value is different from the given number.

4fill in blank

hard

Complete the code to select rows where price is less than or equal to 100.

PostgreSQL

SELECT * FROM products WHERE price [1] 100;

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

A>=

B<=

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' only excludes price equal to 100, which is not correct here.

The operator <= means 'less than or equal to'. Use it to ensure price is not more than 100.

5fill in blank

hard

Fill both blanks to select rows where quantity is greater than 10 and less than 50.

PostgreSQL

SELECT * FROM inventory WHERE quantity [1] 10 AND quantity [2] 50;

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

A>

B<

C;

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of '<' or '>' will include unwanted values.

The operators > and < select quantities strictly between 10 and 50 (exclusive).