Arrow operators (-> and ->>) in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to extract the JSON object field using the arrow operator.

PostgreSQL

SELECT data[1]'name' FROM users;

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

A->

B#>>

C#>

D->>

Attempts:

3 left

💡 Hint

Common Mistakes

Using ->> instead of -> returns text, not JSON.

Using #> or #>> which are for JSON path extraction.

The -> operator extracts a JSON object field as JSON.

2fill in blank

medium

Complete the code to extract the text value of the JSON field using the arrow operator.

PostgreSQL

SELECT data[1]'age' FROM users;

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

A->>

B->

C#>

D#>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using -> instead of ->> returns JSON, not text.

Using #> or #>> which require JSON path arrays.

The ->> operator extracts a JSON object field as text.

3fill in blank

hard

Fix the error in the code to correctly extract the text value from a nested JSON object.

PostgreSQL

SELECT data->'address'[1]'city' FROM users;

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

A->

B->>

C#>

D#>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using ->> for both extractions causes errors.

Using #> or #>> without proper JSON path array.

Use -> to get the nested JSON object address, then ->> to get the text value of city.

4fill in blank

hard

Complete the code to extract the text value of a nested JSON field using arrow operators.

PostgreSQL

SELECT data->'profile'[1]'email' FROM users;

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

A->

B->>

C#>

D#>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using ->> for both blanks causes errors.

Using #> or #>> without JSON path arrays.

First extract the nested JSON object profile with ->, then extract the text value of email with ->>.

5fill in blank

hard

Complete the code to extract the text value of a deeply nested JSON field using arrow operators.

PostgreSQL

SELECT data->'settings'->'notifications'[1]'email' FROM users;

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

A->

B->>

C#>

D#>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using ->> too early causes errors.

Using #> or #>> without JSON path arrays.

Use -> twice to navigate nested JSON objects settings and notifications, then ->> to extract the text value of email.