ZCW-MesoLabs-QueryingPersons.SQL

SQL

The following lab is to be completed using MySQL in your terminal.

To begin import the schema for all of the tables from the following location:

src/main/resources/schema-h2.sql

You must create a database in which to import the schema by accessing mysql through the terminal, then exit and import the schema using:

mysql -u root -p [database] < src/main/resources/schema-h2.sql

Don't submit any changes to the schema file. And, in all reality, you shouldn't be doing anything in there outside of experimenting for your own curiosity.

Guided Walkthrough

Proceed through the sections below, testing out the queries shown and observing the result. Feel free to experiment with your own variations on these queries. This will help to build your familiarity with the process of working with SQL queries.

Insert people into People table

INSERT INTO people (last_name, first_name, mobile, birthday)
VALUES ('Smith', 'John', '230-4293', '1973-01-23');

After doing that insert, go ahead and run all the statements in the data-h2.sql file. That should build out your database enough to get started. Feel free to add more people, though.

My suggestion for the following stuff is, in the H2 console, leave the first line as a SELECT * from whatever tables you're querying. Then, after that, run your queries. That way you can compare the results of your query with the data in the table.

Selecting all rows from table

SELECT * FROM people;

Updating rows

Update firstname for person whose id is 1

UPDATE people SET first_name = 'Tony' WHERE id = 1;

Update mobile where last names are Smith

UPDATE people SET mobile = '152-9854' WHERE last_name = 'Smith';

Update multiple columns with multiple conditions

UPDATE people SET birthday = '1955-01-25' 
WHERE last_name = 'Smith' 
AND id = 4;

UPDATE people SET mobile = '333-3333', last_name = 'Johnson' 
WHERE first_name = 'Noelle' OR first_name = 'Raj';

Basic Functions

SELECT * FROM people;

SELECT COUNT(homenumber) FROM homes;

SELECT homenumber FROM homes WHERE id = 1;

SELECT COUNT(*) FROM homes;

SELECT COUNT(DISTINCT last_name) FROM people;

SELECT  SUM(id), AVG(id) FROM people;

SELECT SUM(id) AS sum, AVG(id) AS avg FROM people;

Notice the difference in the returned table with the aliases?

SELECT MIN(birthday) FROM people;

Strings

SELECT UPPER (first_name), LOWER(last_name) FROM people;

SELECT REPLACE(last_name, 'a', '1') FROM people;

SELECT last_name FROM people;

INSERT INTO people (first_name, last_name, mobile) 
VALUES ('Otto', 'Von Count', '656-6548');

SELECT CONCAT(first_name, last_name) FROM people
WHERE last_name = 'Smith';

SELECT CONCAT(first_name, ' ', last_name) 
FROM people 
WHERE last_name = 'Smith';

SELECT CONCAT_WS(' ',first_name, last_name, mobile) 
FROM people WHERE last_name= 'Smith';

SELECT homenumber, LEFT(homenumber, 3), RIGHT(homenumber, 2) FROM homes;

SELECT LENGTH(address), CHAR_LENGTH(address) FROM homes;

Compare

SELECT first_name, last_name, YEAR(birthday) FROM people WHERE birthday >= '1970-07-06' AND birthday<='1987-07-06';

SELECT first_name, birthday FROM people WHERE first_name='Thomas' OR first_name='Raj' OR first_name='Sheeri';

SELECT first_name, birthday FROM people WHERE first_name IN ('Noelle', 'Thomas', 'Raj');

Wild Cards

SELECT first_name FROM people WHERE RIGHT(first_name,1)='e';

SELECT first_name FROM people WHERE first_name LIKE '%j'; 

SELECT first_name FROM people WHERE first_name LIKE '%o%';

SELECT first_name FROM people WHERE first_name NOT LIKE '%o%';

SELECT COUNT(*) FROM people;

SELECT last_name, COUNT(*) FROM people GROUP BY last_name;

SELECT last_name, GROUP_CONCAT(mobile) FROM people GROUP BY last_name;

SELECT last_name, GROUP_CONCAT(mobile SEPARATOR ' and ') FROM people GROUP BY last_name;

SELECT last_name, GROUP_CONCAT(mobile SEPARATOR ' and ') FROM people GROUP BY last_name  HAVING COUNT(*)>1;

SELECT last_name, GROUP_CONCAT(mobile SEPARATOR ' and ') FROM people WHERE last_name != 'Cabral' GROUP BY last_name  HAVING COUNT(*)>1;

Sorting

SELECT first_name, birthday FROM people ORDER BY birthday;

SELECT first_name, birthday FROM people ORDER BY birthday DESC;

SELECT first_name, last_name FROM people ORDER BY last_name, first_name;

SELECT first_name, birthday FROM people ORDER BY birthday DESC LIMIT 3;

SELECT first_name, MONTHNAME(birthday) as mon, birthday FROM people ORDER BY MONTH(birthday);

SELECT last_name, COUNT(*) FROM  people GROUP BY last_name;

SELECT last_name, COUNT(*) FROM  people GROUP BY last_name ORDER BY NULL;

Inserting and Replacing Records

INSERT INTO people (first_name, last_name, birthday, home_id)
VALUES ('John', 'Smith', '1998-04-07', 4),
('Maya', 'Wasserman' , NULL, 4),
('Paul', 'Thompson', '1996-05-27', 1);

Deleting

DELETE FROM people WHERE first_name='Maya';

SELECT * FROM people;

JOIN

INSERT INTO people (first_name, last_name, birthday)
VALUES ('Eli', 'Kramer', '1984-01-15');

SELECT * FROM people;

SELECT * FROM homes;

SELECT p.first_name, h.address 
FROM people p
INNER JOIN homes h on (p.home_id = h.id);

SELECT first_name, last_name
FROM people p
INNER JOIN homes h on (p.home_id = h.id)
WHERE p.HOME_ID = 1;

SELECT p.*, h.address, h.homenumber
FROM people p
INNER JOIN homes h  on (p.home_id = h.id)
WHERE p.first_name  LIKE '%e%';

Exercise:

Devise a report:

Show all the people in your address table, only if you know their birthday.

Show their name, address and birthday ordered by birthday month, so January birthdays are first.

Devise a report:

Output all information for all people and their home information

Mini Movie Database

Once you have figured out the correct queries for each step, save a copy in a file called src/main/resources/script.sql. This will be how you submit this assignment. If at any time you need to reset the database, you can re-import the database from the .sql file.

Add the following movies to the movies table using an insert statement:

Title	Runtime	Genre	IMDB Score	Rating
Howard the Duck	110	Sci-Fi	4.6	PG
Lavalantula	83	Horror	4.7	TV-14
Starship Troopers	129	Sci-Fi	7.2	PG-13
Waltz With Bashir	90	Documentary	8.0	R
Spaceballs	96	Comedy	7.1	PG
Monsters Inc.	92	Animation	8.1	G

Add a few more movies of your choosing.

Create a query to find all movies in the Sci-Fi genre.

Create a query to find all films that scored at least a 6.5 on IMDB

For parents who have young kids, but who don't want to sit through long children's movies, create a query to find all of the movies rated G or PG that are less than 100 minutes long.

Create a query to show the average runtimes of movies scoring below a 7.5 on imdb, grouped by their respective genres.

There's been a data entry mistake; Starship Troopers is actually rated R, not PG-13. Create a query that finds the movie by its title and changes its rating to R.

Show the ID number and rating of all of the Horror and Documentary movies in the database. Do this in only one query.

This time let's find the average, maximum, and minimum IMDB score for movies of each rating.

That last query isn't very informative for ratings that only have 1 entry. Use a HAVING COUNT(*) > 1 clause to only show ratings with multiple movies showing.

Let's make our movie list more child-friendly. Delete all entries that have a rating of R. Remember to record your query in script.sql.