Array data type in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an integer array column named scores.

PostgreSQL

CREATE TABLE test_scores (id SERIAL PRIMARY KEY, scores [1]);

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AINT

BARRAY

CINTEGER[]

DTEXT[]

Attempts:

3 left

💡 Hint

Common Mistakes

Using ARRAY without specifying the base type.

Using INT instead of INTEGER[].

Using TEXT[] for integer arrays.

In PostgreSQL, to declare an array column of integers, use INTEGER[].

2fill in blank

medium

Complete the code to insert an array of integers into the scores column.

PostgreSQL

INSERT INTO test_scores (scores) VALUES ([1]);

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AARRAY[1, 2, 3]

B'{1,2,3}'

C[1, 2, 3]

D(1, 2, 3)

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets without ARRAY keyword.

Using parentheses instead of ARRAY.

Using string literal without ARRAY keyword.

PostgreSQL uses ARRAY[...] syntax to insert arrays explicitly.

3fill in blank

hard

Fix the error in the query to select the second element of the scores array.

PostgreSQL

SELECT scores[1] FROM test_scores;

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A[2]

B(2)

C<2>

D{2}

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses or curly braces instead of square brackets.

Using zero-based index.

In PostgreSQL, array elements are accessed using square brackets with 1-based indexing.

4fill in blank

hard

Fill both blanks to update the third element of the scores array to 10.

PostgreSQL

UPDATE test_scores SET scores[1] = [2] WHERE id = 1;

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A[3]

B3

C10

D'10'

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the number 10.

Using parentheses instead of square brackets.

Use square brackets to specify the element index and assign the new integer value without quotes.

5fill in blank

hard

Fill all three blanks to select rows where the scores array contains the value 5.

PostgreSQL

SELECT * FROM test_scores WHERE [1] = ANY([2]) AND [3] = 5;

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A5

Bscores

DARRAY[5]

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the value and array column positions.

Using ARRAY[5] inside ANY() instead of the column name.

The ANY operator checks if the value (5) is present in the array column (scores).