From ef42fa5c4656b52ff788bede6b23a2f8e6e1e392 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E2=80=9Cnekosaege=E2=80=9D?= <“nekofreiheit@gmx.de”> Date: Mon, 2 Jun 2025 16:45:43 +0200 Subject: [PATCH] Add SQL queries for various JOIN operations in the documentation --- queries.md | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/queries.md b/queries.md index b06f900..022686c 100644 --- a/queries.md +++ b/queries.md @@ -7,15 +7,18 @@ 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;```
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 +26,9 @@ 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 authors.name, books.* +FROM authors +RIGHT JOIN books ON authors.id = books.author_id; ```
@@ -31,7 +36,9 @@ 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 authors.*, books.* +FROM authors +FULL JOIN books ON authors.id = books.author_id; ```
@@ -41,7 +48,9 @@ 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 +58,9 @@ 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 +68,9 @@ 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 publishers.name AS publisher_name, books.* +FROM publishers +RIGHT JOIN books ON publishers.id = books.publisher_id; ```