queries.md

Answers

Iteration 2

1. Add the solid and chartjs libraries as new rows to the jslibraries table.

INSERT INTO jslibraries(
    name,
    owner,
    description,
    stars,
    url,
    releases,
    licence,
    used_by,
    contributors,
    main_technology,
    type,
    release_date
)
VALUES
(
    'solid',
    'solidjs',
    'A declarative, efficient, and flexible JavaScript library for building user interfaces.',
    10700,
    'solidjs.com',
    194,
    'MIT License',
    624,
    73,
    'typescript',
    'UI Library',
    '2011-08-13'
),
(
    'chartjs',
    'chartjs',
    'Simple HTML5 Charts using the canvas tag.',
    54700,
    'chartjs.org',
    85,
    'MIT License',
    414000,
    377,
    'javascript',
    'Charts Library',
    '2011-11-02'
);

2. Get all the fields of the library that was released earliest (first).

SELECT * FROM jslibraries ORDER BY release_date;

3. Get all the fields of the library that was released most recently (last).

SELECT * FROM jslibraries ORDER BY release_date DESC;

4. All the libraries released before 2015.

SELECT * FROM jslibraries WHERE release_date < '2015-01-01';

5. Get the name and the release_date of the libraries without a licence.

SELECT name, release_date FROM jslibraries WHERE licence IS NULL;

6. Get the name and the stars from all CSS Framework libraries.

SELECT name, stars FROM jslibraries WHERE type = 'CSS Framework';

7. Get the name of the libraries where the main technology is Typescript.

SELECT name FROM jslibraries WHERE main_technology = 'typescript';

8. Get the name and the type of all the libraries with more than 1000 contributors.

SELECT name, type FROM jslibraries WHERE contributors > 1000;

9. Get the total number of stars of all the libraries.

SELECT SUM(stars) FROM jslibraries;

10. Get the average number of contributors for all the libraries.

SELECT AVG(contributors) FROM jslibraries;

11. Update the licence field of the libriaries without a licence to store 'unknown' instead of NULL.

UPDATE jslibraries SET licence = 'unknown' WHERE licence IS NULL;

12. Update the used_by field of the libraries that don't have it specified to store 0 ( i.e., number zero), instead of NULL.

UPDATE jslibraries SET used_by = 0 WHERE used_by IS NULL;

13. Update all the records to capitalize the string provided in the main_technology field.

UPDATE jslibraries SET main_technology = UPPER(main_technology);

14. Delete all the records where licence is 'unknown'.

DELETE FROM jslibraries WHERE licence = 'unknown';

15. Delete all the records with 10000 or less stars.

DELETE FROM jslibraries WHERE stars <= 10000;

16. Delete all the records with less than 100 releases.

DELETE FROM jslibraries WHERE releases < 100;