Diana C.

task-1/queries.sql

@@ -1,27 +1,63 @@
 ---- Queries
 
--- **Question 1** — List the title and published year of every book in the `'Science Fiction'` genre, ordered by published year (oldest first).
 
--- **Question 2** — Show every book published before 1950. Display the title and year only.
+--Question 1** — List the title and published year of every book in the `'Science Fiction'` genre, ordered by published year (oldest first).
+SELECT books.title, books.published_year
+FROM books
+WHERE genre = 'Science Fiction'
+ORDER BY books.published_year ASC;
 
--- **Question 3** — Show every book in the database along with its author's full name. Combine `first_name` and `last_name` into a single column called `author`. _(Hint: you will need a JOIN.)_
+--Question 2** — Show every book published before 1950. Display the title and year only.
+SELECT books.title, books.published_year FROM books
+ WHERE published_year < 1950;
 
--- **Question 4** — List all books written by Stephen King. Show the title and published year, ordered by year. _(Hint: JOIN the two tables and filter on the author's name.)_
 
--- **Question 5** — Add yourself as a new author. Use your real name, or make one up. Pick any nationality and birth year.
+--Question 3** — Show every book in the database along with its author's full name. Combine `first_name` and `last_name` into a single column called `author`. *(Hint: you will need a JOIN.)*
+SELECT b.title, a.first_name || ' ' || a.last_name AS author
+FROM books b
+JOIN authors a ON a.id = b.author_id
 
--- **Question 6** — Add one book for the author you just inserted. It can be a real book or a made-up one.
 
--- **Question 7** — The genre for "The Dark Tower: The Gunslinger" was entered incorrectly as `'Fantasy'`. It should be `'Horror'`. Write an UPDATE to fix it, then verify the change with a SELECT.
+--Question 4** — List all books written by Stephen King. Show the title and published year, ordered by year. *(Hint: JOIN the two tables and filter on the author's name.)*
+SELECT b.title, b.published_year
+FROM books b
+JOIN authors a ON a.id = b.author_id
+WHERE a.first_name = 'Stephen' AND a.last_name = 'King'
+ORDER BY b.published_year;
 
--- **Question 8** — Delete the book you added in Question 6. Make sure your query targets only that specific row.
+--Question 5** — Add yourself as a new author. Use your real name, or make one up. Pick any nationality and birth year.
+INSERT INTO authors (first_name, last_name, nationality, birth_year) 
+VALUES ('Diana', 'Chukhrai', 'Ukrainian', 2001);
 
+
+--Question 6** — Add one book for the author you just inserted. It can be a real book or a made-up one.
+INSERT INTO books (title, published_year, genre, author_id) 
+VALUES ('Spaces',2005, 'Fantasy', 25);
+
+--Question 7** — The genre for "The Dark Tower: The Gunslinger" was entered incorrectly as `'Fantasy'`. It should be `'Horror'`. Write an UPDATE to fix it, then verify the change with a SELECT.
+UPDATE books 
+SET genre = 'Horror'
+WHERE title = 'The Dark Tower: The Gunslinger';
+
+
+
+--Question 8** — Delete the book you added in Question 6. Make sure your query targets only that specific row.
+DELETE FROM books
+WHERE books.id = 101;
 ---
 
 -- ### Bonus questions _(optional)_
 
 -- These cover topics slightly beyond the core material. Have a go if you finish early.
 
--- **Bonus A** — How many books are there per genre? Show the genre name and the count, ordered from most to fewest books.
-
--- **Bonus B** — Find any authors in the database who have no books at all. _(Hint: you will need a LEFT JOIN and check for NULL.)
+--**Bonus A** — How many books are there per genre? Show the genre name and the count, ordered from most to fewest books.
+SELECT genre, COUNT(*) AS book_count
+FROM books
+GROUP BY genre
+ORDER BY book_count DESC;
+
+--**Bonus B** — Find any authors in the database who have no books at all. *(Hint: you will need a LEFT JOIN and check for NULL.)*
+SELECT a.first_name, a.last_name
+FROM authors a
+LEFT JOIN books b ON b.author_id = a.id
+WHERE b.id IS NULL;

task-2/migrate.js

@@ -0,0 +1,39 @@
+import fs from "node:fs";
+import path from "path";
+import Database from "better-sqlite3";
+
+const dataPath = path.join("data", "data.json");
+const data = fs.readFileSync(dataPath, "utf-8");
+const res = JSON.parse(data);
+
+// Open the database file.
+// If the file doesn't exist, better-sqlite3 will create it.
+const db = new Database("data/flashcards.db");
+
+const insertDecks = db.prepare(`
+  INSERT INTO decks (name, description)
+  VALUES (@name, @description)
+`);
+
+for (const deck of res.decks) {
+  insertDecks.run({
+    name: deck.name,
+    description: deck.description,
+  });
+}
+
+
+const insertCards = db.prepare(`
+  INSERT INTO cards (question, answer, learned, deck_id)
+  VALUES (@question, @answer, @learned, @deck_id)
+`);
+
+for (const card of res.cards) {
+  insertCards.run({
+    question: card.question,
+    answer: card.answer,
+    learned: card.learned ? 1 : 0,
+    deck_id: card.deckId
+
+  });
+}