1、nginx加载lua脚本方法可参我的这篇文章

Nginx安装Openresty加载Lua代码_IT东东歌的博客-CSDN博客

2、测试代码

官网 https://github.com/openresty/lua-resty-mysql

local mysql = require "resty.mysql"
local db, err = mysql:new()
if not db then
    ngx.say("failed to instantiate mysql: ", err)
    return
end

db:set_timeout(1000) -- 1 sec

local ok, err, errcode, sqlstate = db:connect{
    host = "127.0.0.1",
    port = 3306,
    database = "test2",
    user = "root",
    password = "2WKE0fI9XTTretNC",
    charset = "utf8",
    max_packet_size = 1024 * 1024,
}

if not ok then
    ngx.say("failed to connect: ", err, ": ", errcode, " ", sqlstate)
    return
end

ngx.say("connected to mysql.")

local res, err, errcode, sqlstate =
    db:query("drop table if exists cats")
if not res then
    ngx.say("bad result: ", err, ": ", errcode, ": ", sqlstate, ".")
    return
end

res, err, errcode, sqlstate =
    db:query("create table cats "
     .. "(id serial primary key, "
     .. "name varchar(5))")
if not res then
    ngx.say("bad result: ", err, ": ", errcode, ": ", sqlstate, ".")
    return
end

ngx.say("table cats created.")

res, err, errcode, sqlstate =
    db:query("insert into cats (name) "
     .. "values (\'Bob\'),(\'\'),(null)")
if not res then
    ngx.say("bad result: ", err, ": ", errcode, ": ", sqlstate, ".")
    return
end

ngx.say(res.affected_rows, " rows inserted into table cats ",
"(last insert id: ", res.insert_id, ")")

-- run a select query, expected about 10 rows in
-- the result set:
res, err, errcode, sqlstate =
    db:query("select * from cats order by id asc", 10)
if not res then
    ngx.say("bad result: ", err, ": ", errcode, ": ", sqlstate, ".")
    return
end

local cjson = require "cjson"
ngx.say("result: ", cjson.encode(res))

-- put it into the connection pool of size 100,
-- with 10 seconds max idle timeout
local ok, err = db:set_keepalive(10000, 100)
if not ok then
    ngx.say("failed to set keepalive: ", err)
    return
end

-- or just close the connection right away:
-- local ok, err = db:close()
-- if not ok then
--     ngx.say("failed to close: ", err)
--     return
-- end

结果

测试结果完毕，实现了nginx和mysql的交互过程。