Minimal database/sql driver.

driver/example_test.go

@@ -0,0 +1,153 @@
+package driver_test
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"os"
+
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
+)
+
+var db *sql.DB
+
+func Example() {
+	// Adapted from: https://go.dev/doc/tutorial/database-access
+
+	// Get a database handle.
+	var err error
+	db, err = sql.Open("sqlite3", "./recordings.db")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+	defer os.Remove("./recordings.db")
+
+	err = setupDatabase()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	albums, err := albumsByArtist("John Coltrane")
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Albums found: %v\n", albums)
+
+	// Hard-code ID 2 here to test the query.
+	alb, err := albumByID(2)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Album found: %v\n", alb)
+
+	albID, err := addAlbum(Album{
+		Title:  "The Modern Sound of Betty Carter",
+		Artist: "Betty Carter",
+		Price:  49.99,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("ID of added album: %v\n", albID)
+
+	// Output:
+	// Albums found: [{1 Blue Train John Coltrane 56.99} {2 Giant Steps John Coltrane 63.99}]
+	// Album found: {2 Giant Steps John Coltrane 63.99}
+	// ID of added album: 5
+}
+
+type Album struct {
+	ID     int64
+	Title  string
+	Artist string
+	Price  float32
+}
+
+func setupDatabase() error {
+	_, err := db.Exec(`DROP TABLE IF EXISTS album`)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.Exec(`
+		CREATE TABLE album (
+			id         INTEGER PRIMARY KEY AUTOINCREMENT,
+			title      VARCHAR(128) NOT NULL,
+			artist     VARCHAR(255) NOT NULL,
+			price      DECIMAL(5,2) NOT NULL
+		)
+	`)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.Exec(`
+		INSERT INTO album
+			(title, artist, price)
+		VALUES
+			('Blue Train', 'John Coltrane', 56.99),
+			('Giant Steps', 'John Coltrane', 63.99),
+			('Jeru', 'Gerry Mulligan', 17.99),
+			('Sarah Vaughan', 'Sarah Vaughan', 34.98)
+	`)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// albumsByArtist queries for albums that have the specified artist name.
+func albumsByArtist(name string) ([]Album, error) {
+	// An albums slice to hold data from returned rows.
+	var albums []Album
+
+	rows, err := db.Query("SELECT * FROM album WHERE artist = ?", name)
+	if err != nil {
+		return nil, fmt.Errorf("albumsByArtist %q: %v", name, err)
+	}
+	defer rows.Close()
+	// Loop through rows, using Scan to assign column data to struct fields.
+	for rows.Next() {
+		var alb Album
+		if err := rows.Scan(&alb.ID, &alb.Title, &alb.Artist, &alb.Price); err != nil {
+			return nil, fmt.Errorf("albumsByArtist %q: %v", name, err)
+		}
+		albums = append(albums, alb)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("albumsByArtist %q: %v", name, err)
+	}
+	return albums, nil
+}
+
+// albumByID queries for the album with the specified ID.
+func albumByID(id int64) (Album, error) {
+	// An album to hold data from the returned row.
+	var alb Album
+
+	row := db.QueryRow("SELECT * FROM album WHERE id = ?", id)
+	if err := row.Scan(&alb.ID, &alb.Title, &alb.Artist, &alb.Price); err != nil {
+		if err == sql.ErrNoRows {
+			return alb, fmt.Errorf("albumsById %d: no such album", id)
+		}
+		return alb, fmt.Errorf("albumsById %d: %v", id, err)
+	}
+	return alb, nil
+}
+
+// addAlbum adds the specified album to the database,
+// returning the album ID of the new entry
+func addAlbum(alb Album) (int64, error) {
+	result, err := db.Exec("INSERT INTO album (title, artist, price) VALUES (?, ?, ?)", alb.Title, alb.Artist, alb.Price)
+	if err != nil {
+		return 0, fmt.Errorf("addAlbum: %v", err)
+	}
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, fmt.Errorf("addAlbum: %v", err)
+	}
+	return id, nil
+}