ruoxi's pull request

your-code/solutions.sql

@@ -0,0 +1,97 @@
+/* Challenge 1 - Who Have Published What At Where?*/
+USE publications;
+SELECT * FROM authors LIMIT 5;
+SELECT * FROM discounts LIMIT 5;
+SELECT * FROM employee LIMIT 5;
+SELECT * FROM jobs LIMIT 5;
+SELECT * FROM pub_info LIMIT 5;
+SELECT * FROM publishers LIMIT 5;
+SELECT * FROM roysched LIMIT 5;
+SELECT * FROM sales LIMIT 5;
+SELECT * FROM stores LIMIT 5;
+SELECT * FROM titleauthor LIMIT 5;
+SELECT * FROM titles LIMIT 5;
+/* From the information in each table, we know that author data(author id, first name and last name) are in table authors;
+publishers contains publisher id and publisher name;
+titleauthor contains author id and title id;
+titles contains title id, title and publisher id;
+Therefore, we can join table titles and table titleauthor, then table author and table publishers. */
+
+DROP TABLE IF EXISTS title_name;
+CREATE TEMPORARY TABLE title_name
+SELECT titleauthor.au_id, titleauthor.title_id, titles.title, titles.pub_id
+FROM titleauthor JOIN titles
+ON titleauthor.title_id = titles.title_id;
+
+SELECT * FROM title_name;
+
+DROP TABLE IF EXISTS au_title_name;
+CREATE TEMPORARY TABLE au_title_name
+SELECT authors.au_id, authors.au_lname, authors.au_fname, title_name.title_id, title_name.title, title_name.pub_id
+FROM authors RIGHT JOIN title_name
+ON authors.au_id = title_name.au_id;
+
+SELECT * FROM au_title_name;
+
+DROP TABLE IF EXISTS au_title_pub;
+CREATE TEMPORARY TABLE au_title_pub
+SELECT au_title_name.au_id AS "AUTHOR ID", 
+au_title_name.au_lname AS "LAST NAME", 
+au_title_name.au_fname AS "FIRST NAME",
+au_title_name.title AS "TITLE", 
+publishers.pub_name AS PUBLISHER
+FROM au_title_name LEFT JOIN publishers
+ON au_title_name.pub_id = publishers.pub_id;
+
+SELECT * FROM au_title_pub;
+
+/* Challenge 2 - Who Have Published How Many At Where? 
+In table au_title_pub, we can count how many records are from the same au_id*/
+
+DROP TABLE IF EXISTS au_title_count;
+CREATE TEMPORARY TABLE au_title_count
+SELECT 
+    `AUTHOR ID`,  -- Backticks used for column alias with spaces
+    `LAST NAME`,  
+    `FIRST NAME`, 
+    `PUBLISHER`,
+    COUNT(TITLE) AS TITLE_COUNT 
+FROM 
+    au_title_pub 
+GROUP BY 
+    `AUTHOR ID`, 
+    `LAST NAME`, 
+    `FIRST NAME`, 
+    `PUBLISHER`;
+
+SELECT * FROM au_title_count;
+
+/* Challenge 3 - Best Selling Authors */
+DROP TABLE IF EXISTS au_tile_sales;
+CREATE TEMPORARY TABLE au_tile_sales
+SELECT au_title_name.au_id AS "AUTHOR ID", 
+au_title_name.au_lname AS "LAST NAME", 
+au_title_name.au_fname AS "FIRST NAME",
+SUM(sales.qty) AS TOTAL
+FROM au_title_name LEFT JOIN sales
+ON au_title_name.title_id = sales.title_id
+GROUP BY
+	`AUTHOR ID`,
+    `LAST NAME`,
+    `FIRST NAME`;
+SELECT * FROM au_tile_sales ORDER BY TOTAL DESC LIMIT 3;
+
+/* Challenge 4 - Best Selling Authors Ranking*/
+
+SELECT authors.au_id AS "AUTHOR ID", 
+authors.au_lname AS "LAST NAME", 
+authors.au_fname AS "FIRST NAME",
+COALESCE(SUM(sales.qty), 0 ) AS TOTAL
+FROM authors LEFT JOIN titleauthor USING (au_id)
+LEFT JOIN titles USING (title_id)
+LEFT JOIN sales USING (title_id)
+GROUP BY
+	`AUTHOR ID`,
+    `LAST NAME`,
+    `FIRST NAME`
+ORDER BY TOTAL DESC;