feat: add appender example

README.md

@@ -100,7 +100,7 @@ defer connector.Close()
 
 ## DuckDB Appender API
 
-If you want to use the [DuckDB Appender API](https://duckdb.org/docs/data/appender.html), you can obtain a new `Appender` by passing a DuckDB connection to `NewAppenderFromConn()`.
+If you want to use the [DuckDB Appender API](https://duckdb.org/docs/data/appender.html), you can obtain a new `Appender` by passing a DuckDB connection to `NewAppenderFromConn()`. See `examples/appender.go` for a complete example.
 
 ```go
 connector, err := duckdb.NewConnector("test.db", nil)

examples/appender.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"log"
+
+	"github.com/marcboeker/go-duckdb"
+)
+
+func main() {
+	c, err := duckdb.NewConnector("", nil)
+	if err != nil {
+		log.Fatalf("could not initialize new connector: %s", err.Error())
+	}
+
+	con, err := c.Connect(context.Background())
+	if err != nil {
+		log.Fatalf("could not connect: %s", err.Error())
+	}
+
+	db := sql.OpenDB(c)
+	if _, err := db.Exec(`CREATE TABLE users (name VARCHAR, age INTEGER)`); err != nil {
+		log.Fatalf("could not create table users: %s", err.Error())
+	}
+
+	a, err := duckdb.NewAppenderFromConn(con, "", "users")
+	if err != nil {
+		log.Fatalf("could not create new appender for users: %s", err.Error())
+	}
+
+	if err := a.AppendRow("Fred", int32(34)); err != nil {
+		log.Fatalf("could not append row to users: %s", err.Error())
+	}
+
+	if err := a.Close(); err != nil {
+		log.Fatalf("could not flush and close appender: %s", err.Error())
+	}
+
+	var (
+		name string
+		age  int
+	)
+	row := db.QueryRowContext(context.Background(), `SELECT name, age FROM users`)
+	if err := row.Scan(&name, &age); err != nil {
+		log.Fatalf("could not retrieve user from db: %s", err.Error())
+	}
+
+	log.Printf("User: name=%s, age=%d", name, age)
+}