update readme and add example

* dcca987 add an old example and a basic one

examples/basic/basic.go

@@ -0,0 +1,40 @@
+package main
+
+import "database/sql"
+
+func recordStats(db *sql.DB, userID, productID int64) (err error) {
+	tx, err := db.Begin()
+	if err != nil {
+		return
+	}
+
+	defer func() {
+		switch err {
+		case nil:
+			err = tx.Commit()
+		default:
+			tx.Rollback()
+		}
+	}()
+
+	if _, err = tx.Exec("UPDATE products SET views = views + 1"); err != nil {
+		return
+	}
+	if _, err = tx.Exec("INSERT INTO product_viewers (user_id, product_id) VALUES (?, ?)", userID, productID); err != nil {
+		return
+	}
+	return
+}
+
+func main() {
+	// @NOTE: the real connection is not required for tests
+	db, err := sql.Open("mysql", "root@/blog")
+	if err != nil {
+		panic(err)
+	}
+	defer db.Close()
+
+	if err = recordStats(db, 1 /*some user id*/, 5 /*some product id*/); err != nil {
+		panic(err)
+	}
+}