我尝试按照http://www.keplerproject.org/luasql/examples.html上的示例进行操作
Lua 5.2.0 Copyright (C) 1994-2011 Lua.org, PUC-Rio
> require "luasql.postgres"
> env = assert (luasql.postgres())
stdin:1: attempt to index global 'luasql' (a nil value)
stack traceback:
stdin:1: in main chunk
[C]: in ?
>
我错过了什么?