Domain types for validation in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a domain named 'positive_int' that only allows integers greater than zero.

PostgreSQL

CREATE DOMAIN positive_int AS INTEGER CHECK (VALUE [1] 0);

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

A=

B>

C<

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' causes the domain to accept only negative numbers.

Using '=' restricts the domain to only zero, not positive numbers.

The domain 'positive_int' should only accept integers greater than zero, so the check condition uses > 0.

2fill in blank

medium

Complete the code to create a domain 'email_text' that only accepts text containing the '@' character.

PostgreSQL

CREATE DOMAIN email_text AS TEXT CHECK (POSITION('[1]' IN VALUE) > 0);

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

A%

B#

C$

D@

Attempts:

3 left

💡 Hint

Common Mistakes

Using '#' or '$' will not correctly validate email addresses.

Forgetting to check the position > 0 means the character might not be present.

The '@' character is essential in email addresses, so the check ensures it appears in the text.

3fill in blank

hard

Fix the error in the domain creation that should restrict a phone number to exactly 10 digits.

PostgreSQL

CREATE DOMAIN phone_number AS TEXT CHECK (LENGTH(VALUE) [1] 10);

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

A=

B>

C<>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' or '<' allows lengths other than 10.

Using '<>' means not equal, which is the opposite of the requirement.

The phone number must have exactly 10 digits, so the length must be equal to 10.

4fill in blank

hard

Fill both blanks to create a domain 'rating' that accepts integers between 1 and 5 inclusive.

PostgreSQL

CREATE DOMAIN rating AS INTEGER CHECK (VALUE [1] 1 AND VALUE [2] 5);

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

A>=

B<

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' or '<' excludes the boundary values 1 or 5.

Using '=' alone only allows one value, not a range.

The rating must be at least 1 (using >=) and at most 5 (using <=) to include both ends.

5fill in blank

hard

Fill all three blanks to create a domain 'zipcode' that accepts exactly 5 digits and only numeric characters.

PostgreSQL

CREATE DOMAIN zipcode AS TEXT CHECK (LENGTH(VALUE) [1] 5 AND VALUE ~ '[2]' AND VALUE !~ '[3]');

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

A=

B^[0-9]{5}$

C[^0-9]

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect regex patterns that allow letters or symbols.

Using '!=' instead of regex operators for pattern matching.

The zipcode must have length exactly 5 (using '='), match the regex for 5 digits (using '^[0-9]{5}$'), and not contain any non-digit characters (using '[^0-9]').