Type casting with :: operator in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to cast the string '123' to an integer using the :: operator.

PostgreSQL

SELECT '123'[1]integer;

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

A->

B=>

C::

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> or => instead of :: for casting.

Trying to use == which is a comparison operator.

The :: operator in PostgreSQL is used to cast a value to a specific type. Here, '123'::integer converts the string to an integer.

2fill in blank

medium

Complete the code to cast the integer 45 to text using the :: operator.

PostgreSQL

SELECT 45[1]text;

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

A->

B::

C=>

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> or => which are not casting operators.

Using == which is for comparison, not casting.

Using 45::text converts the integer 45 to a text string in PostgreSQL.

3fill in blank

hard

Fix the error in the code to correctly cast the string '3.14' to a numeric type.

PostgreSQL

SELECT '3.14'[1]numeric;

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

A->

B=>

C==

D::

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> or => which cause syntax errors.

Using == which is a comparison operator.

The correct way to cast a string to numeric in PostgreSQL is using the :: operator: '3.14'::numeric.

4fill in blank

hard

Fill both blanks to cast the string '2024-06-01' to a date and then to text.

PostgreSQL

SELECT ('2024-06-01'[1]date)[2]text;

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

A::

B->

D=>

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> or => instead of :: for casting.

Forgetting parentheses around the first cast.

First, cast the string to date using ::date, then cast the date to text using ::text.

5fill in blank

hard

Fill all three blanks to cast the string '100' to integer, multiply by 2, and cast the result to text.

PostgreSQL

SELECT (( '100'[1]integer ) * [2] )[3]text;

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

A::

B2

D->

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> instead of :: for casting.

Forgetting to multiply by 2.

Not casting the final result to text.

First cast '100' to integer with ::integer, multiply by 2, then cast the result to text with ::text.