From f261bb5ffc95b2e0787326f5599350d4fffe81d6 Mon Sep 17 00:00:00 2001
From: MohammedAlmatrafi <m1.almatrafi@gmail.com>
Date: Sat, 29 Mar 2025 11:13:41 +0300
Subject: [PATCH] Attempt#1

---
 solutions.sql | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 solutions.sql

diff --git a/solutions.sql b/solutions.sql
new file mode 100644
index 0000000..cbf7864
--- /dev/null
+++ b/solutions.sql
@@ -0,0 +1,66 @@
+-- Challenge 1: List authors, their books, and publishers
+SELECT
+    a.au_id AS author_id,
+    a.au_lname AS last_name,
+    a.au_fname AS first_name,
+    t.title,
+    p.pub_name AS publisher
+FROM authors a
+JOIN titleauthor ta ON a.au_id = ta.au_id
+JOIN titles t ON ta.title_id = t.title_id
+JOIN publishers p ON t.pub_id = p.pub_id;
+
+
+-- Challenge 2: Count of books per author per publisher
+SELECT
+    a.au_id AS author_id,
+    a.au_lname AS last_name,
+    a.au_fname AS first_name,
+    p.pub_name AS publisher,
+    COUNT(t.title_id) AS TITLE_COUNT
+FROM authors a
+JOIN titleauthor ta ON a.au_id = ta.au_id
+JOIN titles t ON ta.title_id = t.title_id
+JOIN publishers p ON t.pub_id = p.pub_id
+GROUP BY a.au_id, p.pub_name
+ORDER BY TITLE_COUNT DESC;
+
+-- Validate total book count
+SELECT SUM(book_count) FROM (
+    SELECT a.au_id, p.pub_name, COUNT(t.title_id) AS book_count
+    FROM authors a
+    JOIN titleauthor ta ON a.au_id = ta.au_id
+    JOIN titles t ON ta.title_id = t.title_id
+    JOIN publishers p ON t.pub_id = p.pub_id
+    GROUP BY a.au_id, p.pub_name
+) AS book_summary;
+
+-- Check if sum matches total entries in titleauthor
+SELECT COUNT(*) FROM titleauthor;
+
+-- Challenge 3: Top 3 authors by sales
+SELECT
+    a.au_id AS author_id,
+    a.au_lname AS last_name,
+    a.au_fname AS first_name,
+    SUM(s.qty) AS total_sales
+FROM authors a
+JOIN titleauthor ta ON a.au_id = ta.au_id
+JOIN titles t ON ta.title_id = t.title_id
+JOIN sales s ON t.title_id = s.title_id
+GROUP BY a.au_id
+ORDER BY total_sales DESC
+LIMIT 3;
+
+-- Challenge 4: Total sales per author, including those with no sales
+SELECT
+    a.au_id AS author_id,
+    a.au_lname AS last_name,
+    a.au_fname AS first_name,
+    COALESCE(SUM(s.qty), 0) AS total_sales
+FROM authors a
+LEFT JOIN titleauthor ta ON a.au_id = ta.au_id
+LEFT JOIN titles t ON ta.title_id = t.title_id
+LEFT JOIN sales s ON t.title_id = s.title_id
+GROUP BY a.au_id
+ORDER BY total_sales DESC;