Advanced SQL Workshop

advancedSqlWorkshop.txt

Create a DB from the following script:
https://gist.github.com/sblondeau/5cdc304b160960bb20c1cd0ba314cf3e

Once the tables are created, write the queries to display:

1. The first name, name and age of the characters
mysql> SELECT firstname, lastname, age FROM Person;

2. The first name, name of the characters and their kingdom, only for those connected to a kingdom
mysql> SELECT ch.firstname, ch.lastname, ki.name 
     > FROM Person AS ch 
     > JOIN Kingdom AS ki ON ki.id=ch.kingdom_id;

3. The same thing including all the characters
mysql> SELECT ch.firstname, ch.lastname, ki.name 
     > FROM Person AS ch 
     > LEFT JOIN Kingdom AS ki ON ki.id=ch.kingdom_id;

4. The average age of the characters
mysql> SELECT AVG(age) AS AverageAge FROM Person;

5. The number of characters per kingdom (include kingdoms with no character)
mysql> SELECT kingdom_id, count(*) AS NumChar FROM Person GROUP BY kingdom_id;

6. The average age by role
mysql> SELECT Role.id, AVG(age) AS AverageAge 
     > FROM Person JOIN Role ON Role.id=Person.role_id 
     > GROUP BY role_id;

7. The average is a little high no? Retrieve then the average of all the characters not being magicians
mysql> SELECT AVG(age) AS AverageAge FROM Person WHERE kingdom_id != 3;

8. List all the characters with their role and possible realm (kingdoms)
mysql> SELECT Person.firstname, Role.role 
     > FROM Person
     > JOIN Role ON Role.id=Person.role_id;

9. Show realms(kingdom) with at least 2 topics
mysql> SELECT Kingdom