Incorrect handling ? placeholder in comments

[tochka]

Driver count ? symbols in comment text

package main

import (
	"database/sql"
	"log"

	_ "github.com/mailru/go-clickhouse"
)

func main() {
	conn, err := sql.Open("clickhouse", "http://127.0.0.1:8123/default?debug=1")
	if err != nil {
		log.Fatal(err)
	}

	if err := conn.Ping(); err != nil {
		log.Fatal(err)
	}
	_, err = conn.Exec(`
			CREATE TABLE IF NOT EXISTS example (
				field1	String				
			) engine=MergeTree(date,field1,8192)
		`)
	if err != nil {
		log.Fatal(err)
	}

	_, err = conn.QueryContext(context.Background(),`
			-- Is it the correct query?
			select * from example
	`)
	if err != nil {
		log.Fatal(err)
	}
}

But I catch dbr: wrong placeholder count error.