new exporter version

testing/go-code-samples/database-sql-package-goproject/multiple/multiple.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/go-sql-driver/mysql"
+)
+
+var db *sql.DB
+
+type Album struct {
+	ID       int64
+	Title    string
+	Artist   string
+	Price    float32
+	Quantity int64
+}
+
+func main() {
+	// Capture connection properties.
+	cfg := mysql.Config{
+		User:   os.Getenv("DBUSER"),
+		Passwd: os.Getenv("DBPASS"),
+		Net:    "tcp",
+		Addr:   "127.0.0.1:3306",
+		DBName: "recordings",
+	}
+	// Get a database handle.
+	var err error
+	db, err = sql.Open("mysql", cfg.FormatDSN())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	pingErr := db.Ping()
+	if pingErr != nil {
+		log.Fatal(pingErr)
+	}
+	fmt.Println("Connected!")
+
+	albums, err := albumsByArtist("John Coltrane")
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Albums found: %v\n", albums)
+}
+
+// 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, &alb.Quantity); 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
+}