D语言dstddb库使用sqlite会少第一行问题

import std.database.front;
import std.database.sqlite.database;

auto url = "path://./core.sdb";
auto db = new Database!DefaultPolicy(url);
auto conn = db.connection();

auto data = conn.query("select * from cfg");
auto rows = data.rows;
foreach (r; rows) {
    auto tmp = r[0].as!string;
    writeln(tmp);
}