complete implementation

README.md

@@ -1,9 +1,24 @@
-# WORK IN PROGRESS - go-sqlite-demo
+# Project to demo SQLite + Go
 
-A demo project to demo SQLite + Go
+This repository contains an illustration of how to interact with a SQLite
+database using `database/sql` and `https://pkg.go.dev/modernc.org/sqlite`.
 
-- database/sql
-- https://pkg.go.dev/modernc.org/sqlite
+The example is intentionally chosen to match that of the official Go Project
+tutorial, [Accessing a relational database](https://go.dev/doc/tutorial/database-access)
+which uses MySQL as the database server.
 
+## Why SQLite?
 
-https://go.dev/doc/tutorial/database-access
+SQLite is perfect for [many use cases](https://www.sqlite.org/whentouse.html).
+
+My choice of using SQLite for this demo is that it is perfect to illustrate how
+we can persist data to a SQL database from Go.
+
+## Why modernc.org/sqlite?
+
+It's CGO free which means, we don't have to worry about installation woes
+(potential) on different operating systems and architecture
+
+## Explanations of the code 
+
+See [this blog post](TBD).

app.go

@@ -29,7 +29,12 @@ func initDatabase(dbPath string) error {
 	}
 	_, err = db.ExecContext(
 		context.Background(),
-		`CREATE TABLE IF NOT EXISTS album (id INTEGER, title TEXT NOT NULL, artist TEXT NOT NULL, price REAL NOT NULL)`,
+		`CREATE TABLE IF NOT EXISTS album (
+			id INTEGER PRIMARY KEY AUTOINCREMENT, 
+			title TEXT NOT NULL, 
+			artist TEXT NOT NULL, 
+			price REAL NOT NULL
+		)`,
 	)
 	if err != nil {
 		return err
@@ -42,31 +47,49 @@ func addAlbum(a *Album) (int64, error) {
 		context.Background(),
 		`INSERT INTO album (title, artist, price) VALUES (?,?,?);`, a.Title, a.Artist, a.Price,
 	)
-	rows, err := result.RowsAffected()
+	id, err := result.LastInsertId()
 	if err != nil {
 		return 0, err
 	}
-	return rows, nil
+	return id, nil
 }
 
-func albumsByArtist(artist string) ([]*AlbumDbRow, error) {
-	result, err := db.QueryContext(
+func albumsByArtist(artist string) ([]AlbumDbRow, error) {
+
+	var albums []AlbumDbRow
+	rows, err := db.QueryContext(
 		context.Background(),
-		`INSERT INTO album (title, artist, price) VALUES (?,?,?);`, a.Title, a.Artist, a.Price,
+		`SELECT * FROM album WHERE artist=?;`, artist,
 	)
-	rows, err := result.RowsAffected()
 	if err != nil {
-		return 0, err
+		return nil, err
 	}
-	return rows, nil
-
-	return nil, nil
+	defer rows.Close()
+	for rows.Next() {
+		var album AlbumDbRow
+		if err := rows.Scan(
+			&album.ID, &album.Title, &album.Artist, &album.Price,
+		); err != nil {
+			return nil, err
+		}
+		albums = append(albums, album)
+	}
+	return albums, err
 }
 
-func albumByID(id int) (*AlbumDbRow, error) {
-	return nil, nil
+func albumByID(id int) (AlbumDbRow, error) {
+	var album AlbumDbRow
+	row := db.QueryRowContext(
+		context.Background(),
+		`SELECT * FROM album WHERE id=?`, id,
+	)
+	err := row.Scan(&album.ID, &album.Title, &album.Artist, &album.Price)
+	if err != nil {
+		return album, err
+	}
+	return album, nil
 }
 
 func main() {
-	fmt.Println("HELLO")
+	fmt.Println("HELLO WORLD. Please run go test")
 }

app_test.go

@@ -21,10 +21,10 @@ func TestInsertAndQueryData(t *testing.T) {
 		{"Blue Train", "John Coltrane", 56.99},
 	}
 
-	for _, album := range testData {
-		rowCnt, err := addAlbum(&album)
-		if rowCnt != 1 {
-			t.Fatalf("expected inserted row count: 1, got: %d", rowCnt)
+	for idx, album := range testData {
+		lastInsertId, err := addAlbum(&album)
+		if lastInsertId != int64(idx+1) {
+			t.Fatalf("expected inserted ID: %d, got: %d", idx+1, lastInsertId)
 		}
 		if err != nil {
 			t.Fatalf("error inserting row: %v", err)
@@ -40,8 +40,19 @@ func TestInsertAndQueryData(t *testing.T) {
 		t.Fatalf("error querying data: %v", err)
 	}
 
-	if !reflect.DeepEqual(gotAlbums, expectedAlbums) {
-		t.Fatalf("expected: %#v, got: %#v", expectedAlbums, gotAlbums)
+	if len(gotAlbums) != len(expectedAlbums) {
+		t.Fatalf("expected to get: %d albums as result, got: %d", len(expectedAlbums), len(gotAlbums))
+	}
+
+	gotAlbumMap := make(map[int]AlbumDbRow)
+	for _, a := range gotAlbums {
+		gotAlbumMap[a.ID] = a
+	}
+
+	for _, a := range expectedAlbums {
+		if _, ok := gotAlbumMap[a.ID]; !ok {
+			t.Error("expected to get album with ID:", a.ID)
+		}
 	}
 
 	expectedAlbum := AlbumDbRow{