From 2edb9022d99380b2507226e84ee0ac517e35b812 Mon Sep 17 00:00:00 2001 From: Florian Wunsch Date: Mon, 2 Jun 2025 14:42:04 +0200 Subject: [PATCH] done --- queries.md | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/queries.md b/queries.md index b06f900..1da6ddd 100644 --- a/queries.md +++ b/queries.md @@ -7,7 +7,9 @@ 1. Using an **INNER JOIN**, list all books (left table) that have an assigned author (right table). The result should include only books with assigned authors. ```sql --- Your Query Goes Here +SELECT books.* +FROM books +INNER JOIN authors ON books.author_id = authors.id; ```
@@ -15,7 +17,10 @@ 2. Using a **LEFT JOIN**, list all authors (left table) and their corresponding books on the (right table). The result should include all authors, including those who don't have any books assigned. ```sql --- Your Query Goes Here +SELECT authors.*, books.title +FROM authors +LEFT JOIN books ON authors.id = books.author_id; + ```
@@ -23,7 +28,9 @@ 3. Using a **RIGHT JOIN**, list all books (right table) and their corresponding authors on the (left table). The result should include books without assigned authors. ```sql --- Your Query Goes Here +SELECT books.*, authors.name AS author_name +FROM authors +RIGHT JOIN books ON authors.id = books.author_id; ```
@@ -31,7 +38,9 @@ 4. Using a **FULL JOIN**, list all records from the `books` and `authors` tables. The result should include all details from both tables, even if there are no match. ```sql --- Your Query Goes Here +SELECT books.*, authors.name AS author_name +FROM books +FULL JOIN authors ON books.author_id = authors.id; ```
@@ -41,7 +50,9 @@ 1. Using an **INNER JOIN**, list all books (left table) and their corresponding publishers on the (right table). The result should include the book's title, publisher's name, and location. ```sql --- Your Query Goes Here +SELECT books.title, publishers.name AS publisher_name, publishers.location +FROM books +INNER JOIN publishers ON books.publisher_id = publishers.id; ```
@@ -49,7 +60,9 @@ 2. Using a **LEFT JOIN**, list all publishers (left table) and any books they have published on the (right table). The result should include all publishers, including those who haven't published any books. ```sql --- Your Query Goes Here +SELECT publishers.*, books.title +FROM publishers +LEFT JOIN books ON publishers.id = books.publisher_id; ```
@@ -57,7 +70,9 @@ 3. Using a **RIGHT JOIN**, list all books (right table) and their corresponding publishers on the (left table). The result should include all books, even those without a linked publisher. ```sql --- Your Query Goes Here +SELECT books.*, publishers.name AS publisher_name +FROM publishers +RIGHT JOIN books ON publishers.id = books.publisher_id; ```
@@ -65,7 +80,10 @@ 4. Using a **FULL JOIN**, list all records from the `authors`, `books`, and `publishers` tables. The result should include all records from the three tables, even if there are no matches between them. ```sql --- Your Query Goes Here +SELECT books.title, authors.name AS author_name, publishers.name AS publisher_name +FROM books +FULL JOIN authors ON books.author_id = authors.id +FULL JOIN publishers ON books.publisher_id = publishers.id; ```