建立与 RethinkDB 的连接

const r = require（rethinkdb）;

 placeholderCopyr.connect({host: 'localhost', port: 28015}, (conn) => console.log(conn))

// Or as a promise
 
let rdb_conn;
r.connect({host: 'localhost', port: 28015}).then((conn) => {
  rdb_conn = conn;
}).then(() => {
  // Continue to use rdb_conn
});