lab solved

queries.md

@@ -6,96 +6,137 @@
 
 **1. Add the `solid` and `chartjs` libraries as new rows to the `jslibraries` table.**
 
-<!-- Your Query Goes Here -->
+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')
 
 <br>
 
 **2. Get all the fields of the library that was released earliest (first).**
 
 <!-- Your Query Goes Here -->
 
+select \*
+from jslibraries
+where release_date='2011-08-13'
+
 <br>
 
 **3. Get all the fields of the library that was released most recently (last).**
 
 <!-- Your Query Goes Here -->
 
+select \*
+from jslibraries
+where release_date='2018-08-12'
 <br>
 
 **4. All the libraries released before 2015.**
 
 <!-- Your Query Goes Here -->
 
+select \*
+from jslibraries
+where release_date < '2015-01-01'
+
 <br>
 
 **5. Get the `name` and the `release_date` of the libraries without a licence.**
 
 <!-- Your Query Goes Here -->
 
+select \*
+from jslibraries
+where licence is null
+
 <br>
 
 **6. Get the `name` and the `stars` from all CSS Framework libraries.**
 
 <!-- Your Query Goes Here -->
 
+select name, stars
+from jslibraries
+where type = 'CSS Framework'
+
 <br>
 
 **7. Get the `name` of the libraries where the main technology is Typescript.**
 
 <!-- Your Query Goes Here -->
 
+select name
+from jslibraries
+where main_technology = 'typescript'
+
 <br>
 
 **8. Get the `name` and the `type` of all the libraries with more than 1000 contributors.**
 
 <!-- Your Query Goes Here -->
 
+select name, type
+from jslibraries
+where contributors > 1000
+
 <br>
 
 **9. Get the total number of `stars` of all the libraries.**
 
 <!-- Your Query Goes Here -->
 
+select sum(stars) as Total_Stars
+from jslibraries
+
 <br>
 
 **10. Get the average number of `contributors` for all the libraries.**
 
 <!-- Your Query Goes Here -->
 
+select avg(contributors) as average_contributors
+from jslibraries
 <br>
 
 **11. Update the `licence` field of the libriaries without a licence to store `'unknown'` instead of `NULL`.**
 
 <!-- Your Query Goes Here -->
 
+update jslibraries set licence='unknown' where licence is null
 <br>
 
 **12. Update the `used_by` field of the libraries that don't have this information to store `'unknown'` instead of `NULL`.**
 
 <!-- Your Query Goes Here -->
 
+update jslibraries set used_by=0 where used_by is null
+
 <br>
 
 **13. Update all the records to capitalize the string provided in the `main_technology` field.**
 
 <!-- Your Query Goes Here -->
 
+update jslibraries set main_technology=UPPER(main_technology)
 <br>
 
 **14. Delete all the records where `licence` is `'unknown'`.**
 
 <!-- Your Query Goes Here -->
 
+delete from jslibraries where licence='unknown'
 <br>
 
 **15. Delete all the records with 10000 or less `stars`.**
 
 <!-- Your Query Goes Here -->
 
+delete from jslibraries where stars < 10000
 <br>
 
 **16. Delete all the records with less than 100 `releases`.**
 
 <!-- Your Query Goes Here -->
 
+delete from jslibraries where releases < 100
 <br>