Lee

i checked the source, i cannot find any qrcode encode interface, why not?

zxing-cpp has no any write interface, but qrcode provide it.

可以，直接上代码不？ :)

when query failed， need to close db connection, so you need to do as below: `res, err, errcode, sqlstate = db:query("select * from country limit 1") if not res then...