Assignement_Part2_SQL

SQL-part-1-Studio.sql

@@ -0,0 +1,83 @@
+
+--Question 1: Write a query of the `books` table that returns the top 100 results and includes `book_id`, `authors`, `title`, and `average_rating`. Use an alias for at least one column and sort the result set in descending order of rating. What is the number one book?
+SELECT TOP 100
+    book_id,
+    authors,
+    title AS book_title,     -- alias for title
+    average_rating
+FROM [BooksDB].[dbo].[books]
+ORDER BY average_rating DESC;
+
+
+--Question 2: Write a query to find the least popular book.
+
+SELECT TOP 1 book_id, title, authors, average_rating
+FROM [BooksDB].[dbo].[books]
+ORDER BY average_rating ASC;
+
+--Question 3: Which tag is the most popular?
+
+SELECT TOP 1 
+    tag_id, "count"
+FROM [BooksDB].[dbo].[book_tags]
+ORDER BY "count" DESC;
+
+--Question 4: What is the name of the most popular tag?
+
+SELECT *
+FROM BooksDB.dbo.tags
+WHERE tag_id = (
+
+SELECT TOP (1) tag_id
+
+FROM BooksDB.dbo.book_tags
+
+ ORDER BY "count" DESC)
+
+
+--Question 5: How many books where released in the first decade of 2000?
+
+SELECT COUNT(*) AS books_2000s
+FROM [BooksDB].[dbo].[books]
+WHERE original_publication_year BETWEEN 2000 AND 2009;
+
+--Question 6: How many book titles contain the word, "happy"?
+
+SELECT COUNT(*) AS happy_books
+FROM [BooksDB].[dbo].[books]
+WHERE title LIKE '%happy%';
+
+--Question 7: List the books from the top 3 authors from Question 1. 
+-- If there is more than one author just use the first one. Sort the title alphabetically by `author` and then by `average_rating`, best rated to lowest. Does this order matter in sorting?
+
+ SELECT authors, title, average_rating
+FROM BooksDB.dbo.books
+WHERE authors = 'j.k. rowling' OR authors = 'bill watterson' OR authors = 'brandon sanderson'
+ORDER BY title ASC, average_rating DESC
+
+--Question 8: Write a query that returns the number of authors whose first name is between rock and roll.
+SELECT COUNT(*) AS authors_between_rock_roll
+FROM [BooksDB].[dbo].[books]
+WHERE authors BETWEEN 'rock' AND 'roll';
+
+-- Question:  Click here to add a questions that you want to answer and write a query to find 
+the answer!
+
+--Question-Returns the top 100 books sorted by average_rating (highest first).
+SELECT TOP 100
+    book_id,
+    authors,
+    title AS book_title,
+    average_rating
+FROM [BooksDB].[dbo].[books]
+ORDER BY average_rating DESC;
+
+--question-Books containing the word "happy"
+
+SELECT COUNT(*) AS happy_books
+FROM [BooksDB].[dbo].[books]
+WHERE title LIKE '%happy%';
+
+
+
+

SQL-part-1-exercises.sql

@@ -0,0 +1,120 @@
+
+--A. The books table 
+
+--Question 1 Select the top 1000 rows from the books table.make sure to use the correct syntax for your SQL database.
+SELECT Top 1000 *
+FROM [BooksDB].[dbo].[books]
+
+--Question 2 count the number of Titles .Are there  1000 titles as promised by the dataset?
+
+SELECT COUNT(Title) AS Number_of_Titles
+FROM [BooksDB].[dbo].[books]
+
+--Question 3 Count the number of books where  the original_publication_year is earlier than 1800?
+
+SELECT COUNT(Title) AS Books_Before_1800
+FROM [BooksDB].[dbo].[books]
+WHERE original_publication_year < 1800  
+
+--Question 4 Create the query that display distinct authors from the table?
+
+SELECT DISTINCT authors
+FROM [BooksDB].[dbo].[books]    
+ORDER BY authors
+
+--Question 5 Create the query that display acount of all the books that contains a language_code for english.this could be represented in a table as "en" or "eng".
+
+SELECT COUNT(Title) AS english
+FROM [BooksDB].[dbo].[books]
+WHERE language_code IN ('en', 'eng')    
+
+--Question 6 Create the query that checks how many original titles where written during world war 1 era (1914-1921)?
+
+SELECT COUNT(Title) AS WW1_Era
+FROM [BooksDB].[dbo].[books]
+WHERE original_publication_year BETWEEN 1914 AND 1921
+
+
+--B.The Books tags table
+--Question 1 Select the top 1000 table items ordered by the tag_id?
+
+SELECT TOP 1000 *
+FROM [BooksDB].[dbo].[book_tags]    
+ORDER BY tag_id
+
+--Question 2 create a query that counts the number of good_books_id grouped by tag_id ?
+
+select COUNT(goodreads_book_id) as good_reads
+FROM [BooksDB].[dbo].[book_tags]
+GROUP BY tag_id
+
+--Question 3 In the last query ,we created new,unnamed column .use As to create Alias to provide a name of your choice to this column?
+
+select COUNT(goodreads_book_id) as Goodreads_books
+FROM [BooksDB].[dbo].[book_tags]
+GROUP BY tag_id
+
+--C. The rating table
+--Question 1 create a query that selects the top 1000 rows from the ratings table in a descnding order?
+
+SELECT TOP 1000 *
+FROM [BooksDB].[dbo].[ratings]
+ORDER BY rating DESC  
+
+--question 2 Create a query that returns the total number of user that has given a rating less than 2?
+
+select COUNT(rating) as total_ratings
+from [BooksDB].[dbo].[ratings]
+where rating < 2
+
+--Question 3 Create a query that returns the sum of books that have rating 4 or higher?
+
+select COUNT(rating) as total_ratings
+from [BooksDB].[dbo].[ratings]
+where rating >= 4
+
+
+--D. The Tags Table
+--Question 1 Create a query that return table items where the tag_name describes book as a mystery?
+
+SELECT * 
+from [BooksDB].[dbo].[tags]
+WHERE tag_name LIKE '%mystery%'
+
+--Questtion 2 run the query below. in your worlds what is returning?
+
+SELECT *
+FROM BooksDB.dbo.tags
+WHERE tag_name < 'd' AND tag_name >= 'c';
+
+--The to Read table 
+--Question 1:  Create a query that uses the `user_id` to count the total number of books that each user wants to read.  Print the results in ascending order by `user_id` under the alias 'Total Books To Read'.
+
+--Hint: You can use both `GROUP BY` and `ORDER BY` to complete this query.
+
+SELECT user_id, COUNT(book_id) AS 'Total Books To Read'
+FROM [BooksDB].[dbo].[to_read]
+GROUP BY user_id
+ORDER BY user_id ASC
+
+--Question 2: Create a query that uses `user_id` to count the total number of books each user wants to read.  Have the results sort the table by the total number of `book_ids` in descending order and under the alias 'Total Books To Read'.
+
+--Hint: You can use both `GROUP BY` and `ORDER BY` to complete this query.
+
+SELECT user_id, COUNT(book_id) AS 'Total Books To Read'
+FROM [BooksDB].[dbo].[to_read]
+GROUP BY user_id
+ORDER BY COUNT(book_id) DESC
+
+
+
+
+
+
+
+
+
+
+
+
+

SQL-part-4-demos.sql

@@ -0,0 +1,169 @@
+--1which driver have ever finished first?
+
+SELECT forename, surname
+FROM formula_one.dbo.drivers
+WHERE driverId IN   
+(
+	SELECT DISTINCT driverId
+	FROM formula_one.dbo.results
+	WHERE position = '1'
+)
+
+--2 How many races has each driver entered?
+
+SELECT d.forename, d.surname, 
+(
+    SELECT COUNT(*) 
+ FROM formula_one.dbo.results AS r
+ WHERE r.driverId = d.driverId
+ ) AS race_count
+FROM formula_one.dbo.drivers AS d
+
+--Which driver have entered at least 50 competitions?
+
+SELECT
+    d.forename, d.surname
+FROM formula_one.dbo.drivers AS d
+WHERE
+(
+    SELECT COUNT(*) 
+    FROM formula_one.dbo.results AS r
+    WHERE r.driverId = d.driverId
+) >= 50
+
+--which driver have finished first at least once? CTE version
+WITH Winning_driverIDs AS(
+    SELECT DISTINCT driverId
+    FROM formula_one.dbo.results
+    WHERE position = '1'            
+
+)
+SELECT d.forename, d.surname
+FROM formula_one.dbo.drivers AS d
+WHERE d.driverId IN (SELECT driverId FROM Winning_driverIDs);   
+
+-- for each circuit,in how many years has it hosted at least one race?
+--count of distinct year values for each circuit id, from race table
+--information about each circuit itself,like the circuit name,which comes from the circuit table
+
+WITH circuit_years AS
+(
+Select circuitId,COUNT(DISTINCT year) AS num_years_hosted
+from formula_one.dbo.races
+GROUP BY circuitId
+)
+SELECT cir.name AS circuit_name,
+cy.num_years_hosted
+FROM formula_one.dbo.circuits AS cir
+INNER JOIN circuit_years AS cy
+ON cir.circuitId = cy.circuitId
+ORDER BY cy.num_years_hosted DESC;
+
+-- which drivers have scored points in more than 5 different races?
+--need: driver table, results
+
+WITH driver_points AS ( SELECT
+   driverId,
+    COUNT(resultId) AS races_with_points
+FROM formula_one.dbo.results
+WHERE points > 0
+GROUP BY driverId
+)
+SELECT d.forename ,d.surname,
+driver_points.races_with_points AS races_with_points
+FROM formula_one.dbo.drivers AS d
+INNER JOIN driver_points
+ON d.driverId = driver_points.driverId
+WHERE driver_points.races_with_points > 5
+ORDER BY races_with_points;
+
+-- A list of all driver who are either from the UK or from Italy
+SELECT forename,surname,nationality
+From formula_one.dbo.drivers
+WHERE
+nationality = 'British'
+
+UNION 
+
+SELECT forename,surname,nationality
+From formula_one.dbo.drivers
+WHERE
+nationality = 'Italian'
+
+--list of drivers who have either won a race ,or recorded the fastet lap in a race
+--"rank "column in results table is the "rank "of the fastest lap.i.e a rank of 1 means they had the first fastet lap in that race
+-- table that pulls drivers who won a race
+
+SELECT
+    d.forename, d.surname,
+    'Race Winner' AS achievement_type
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS r
+ON d.driverId = r.driverId
+WHERE r.position = '1'
+UNION
+--table that pulls driver who have recorded the fastet lap in a race
+SELECT
+    d.forename, d.surname,
+    'Fastest Lap' AS achievement_type   
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS r
+ON d.driverId = r.driverId
+WHERE r.rank = '1';
+
+-- create a list of drivers who races in both 2021 and 2022
+
+--create a table of drivers whoc raced in 2021
+
+SELECT DISTINCT d.driverId,
+d.forename,
+d.surname
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS res
+ON d.driverID = res.driverId
+INNER JOIN formula_one.dbo.races
+ON res.raceId = races.raceId
+WHERE races.year=2021
+
+INTERSECT
+--table of drivers who races in 2022
+
+SELECT DISTINCT d.driverId,
+d.forename,
+d.surname
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS res
+ON d.driverID = res.driverId
+INNER JOIN formula_one.dbo.races
+ON res.raceId = races.raceId
+WHERE races.year=2022
+
+--which driver raced in 2021 but not 2022
+
+SELECT DISTINCT d.driverId,
+d.forename,
+d.surname
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS res
+ON d.driverID = res.driverId
+INNER JOIN formula_one.dbo.races
+ON res.raceId = races.raceId
+WHERE races.year=2021
+
+EXCEPT
+--table of drivers who races in 2022
+
+SELECT DISTINCT d.driverId,
+d.forename,
+d.surname
+FROM formula_one.dbo.drivers AS d
+INNER JOIN formula_one.dbo.results AS res
+ON d.driverID = res.driverId
+INNER JOIN formula_one.dbo.races
+ON res.raceId = races.raceId
+WHERE races.year=2022
+
+
+
+
+