JG Done lab-mysql-select

your-code/solutions.sql

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+USE Publications;
+
+/* CHALLENGE 1*/ 
+
+SELECT * FROM authors; 
+SELECT * FROM Publications.titleauthor; 
+SELECT * FROM Publications.titles; 
+SELECT * FROM Publications.publishers;
+
+
+/* ADDING ONLY THE TITLE ID*/
+SELECT 
+    authors.au_id,
+    authors.au_lname,
+    authors.au_fname,
+    titleauthor.au_id,
+    titleauthor.title_id
+FROM
+    authors
+LEFT JOIN
+	titleauthor 
+ON 
+	authors.au_id = titleauthor.au_id;
+
+/*ADDIND THE OTHER TABLES*/ 
+
+SELECT 
+    authors.au_id AS Author_ID,
+    authors.au_lname AS Last_name,
+    authors.au_fname AS First_Name,
+    titles.title AS Title,
+    publishers.pub_name AS Publisher
+FROM
+    authors
+LEFT JOIN
+	titleauthor 
+ON 
+	authors.au_id = titleauthor.au_id
+LEFT JOIN
+	titles
+ON
+    titleauthor.title_id = titles.title_id
+LEFT JOIN 
+	publishers
+ON 
+	titles.pub_id = publishers.pub_id;
+
+/* CHALLENGE 2 */ 
+
+SELECT 
+    authors.au_id AS Author_ID,
+    authors.au_lname AS Last_name,
+    authors.au_fname AS First_Name,
+    publishers.pub_name AS Publisher,
+    COUNT(titles.title_id) AS Title_count
+FROM
+    authors
+LEFT JOIN
+	titleauthor 
+ON 
+	authors.au_id = titleauthor.au_id
+LEFT JOIN
+	titles
+ON
+    titleauthor.title_id = titles.title_id
+LEFT JOIN 
+	publishers
+ON 
+	titles.pub_id = publishers.pub_id
+GROUP BY 
+authors.au_id, authors.au_lname, authors.au_fname, publishers.pub_name;     
+
+/* CHALLENGE 3 */ 
+
+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_sales
+FROM 
+    authors
+LEFT JOIN 
+    titleauthor ON titleauthor.au_id = authors.au_id
+LEFT JOIN 
+    titles ON titles.title_id = titleauthor.title_id
+LEFT JOIN
+    sales ON sales.title_id = titles.title_id
+GROUP BY
+    authors.au_id, authors.au_lname, authors.au_fname
+ORDER BY
+    total_sales DESC
+LIMIT 3;
+
+/* CHALLENGE 4 */ 
+
+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_sales
+FROM 
+    authors
+LEFT JOIN 
+    titleauthor ON titleauthor.au_id = authors.au_id
+LEFT JOIN 
+    titles ON titles.title_id = titleauthor.title_id
+LEFT JOIN
+    sales ON sales.title_id = titles.title_id
+GROUP BY
+    authors.au_id, authors.au_lname, authors.au_fname
+ORDER BY
+    total_sales DESC;