[vtable] Add pure Go example of GitHub repo vtable.

_example/vtable/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"github.com/mattn/go-sqlite3"
+	"log"
+)
+
+func main() {
+	sql.Register("sqlite3_with_extensions", &sqlite3.SQLiteDriver{
+		ConnectHook: func(conn *sqlite3.SQLiteConn) error {
+			return conn.CreateModule("github", githubModule{})
+		},
+	})
+	db, err := sql.Open("sqlite3_with_extensions", ":memory:")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec("create virtual table repo using github(id, full_name, description, html_url)")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	rows, err := db.Query("select id, full_name, description, html_url from repo")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var id, full_name, description, html_url string
+		rows.Scan(&id, &full_name, &description, &html_url)
+		fmt.Printf("%s: %s\n\t%s\n\t%s\n\n", id, full_name, description, html_url)
+	}
+}