Goでsqliteを操作しようとすると `Error: file is not a database` と出る。

Go
|-main.go
|-example.sql

というフォルダ構成になっています。

この状態で以下のようにGoでsqliteを操作しようとすると Error: file is not a database
というエラーが出ます。

terminal

○MacBook-puro:Go user名$ sqlite3 example.sql
SQLite version 3.24.0 2018-06-04 14:10:15
Enter ".help" for usage hints.
sqlite> .table
Error: file is not a database
sqlite>

example.sql

package main
import (
"database/sql"
"fmt"
"log"
    _ "github.com/mattn/go-sqlite3"
)

var DbConnection *sql.DB

func main() {
	DbConnection, _ := sql.Open("sqlite3", "./example.sql")
	defer DbConnection.Close()
	cmd := `CREATE TABLE IF NOT EXISTS person(
		name STRING,
		age INT)`
	_, err := DbConnection.Exec(cmd)
	if err != nil {
		log.Fatalln(err)
	}
}

こちらを参考にファイル名から .sql を消してみても解決しません。

補足で、ruby関連の操作をすると

Ignoring bindex-0.5.0 because its extensions are not built.  Try: gem pristine bindex --version 0.5.0
Ignoring byebug-10.0.2 because its extensions are not built.  Try: gem pristine byebug --version 10.0.2
Ignoring byebug-10.0.1 because its extensions are not built.  Try: gem pristine byebug --version 10.0.1
Ignoring byebug-10.0.0 because its extensions are not built.  Try: gem pristine byebug --version 10.0.0
Ignoring ffi-1.9.23 because its extensions are not built.  Try: gem pristine ffi --version 1.9.23
Ignoring mysql2-0.4.10 because its extensions are not built.  Try: gem pristine mysql2 --version 0.4.10
Ignoring nio4r-2.3.1 because its extensions are not built.  Try: gem pristine nio4r --version 2.3.1
Ignoring nio4r-2.3.0 because its extensions are not built.  Try: gem pristine nio4r --version 2.3.0
Ignoring nio4r-2.2.0 because its extensions are not built.  Try: gem pristine nio4r --version 2.2.0
Ignoring nokogiri-1.8.2 because its extensions are not built.  Try: gem pristine nokogiri --version 1.8.2
Ignoring puma-3.11.4 because its extensions are not built.  Try: gem pristine puma --version 3.11.4
Ignoring puma-3.11.3 because its extensions are not built.  Try: gem pristine puma --version 3.11.3
Ignoring sqlite3-1.3.13 because its extensions are not built.  Try: gem pristine sqlite3 --version 1.3.13
Ignoring websocket-driver-0.6.5 because its extensions are not built.  Try: gem pristine websocket-driver --version 0.6.5

のような警告文がでます。

ここら辺が関係しているかもしれないと考えていますが解決方法が分かりません。（ruby, rbenvの再インストールも行いました。）

ご教授いただけると幸いです。