Lua 操作 MongoDB 数据库实例

比眉伴天荒 2023-10-17 17:00 18阅读 0赞

最近有个工作是使用Nginx + Lua实现一个操作MongoDB数据库的API，主要实现其count和query功能。之前没有写过Lua，于是也就勉强着上手，在cloudwu的 lua-mongo 的基础上实现了操作MongoDB的API。

cloudwu的lua-mongo驱动实现了连接Mongo，进行find和findOne等基本操作的功能，所以在lua-mongo的基础上增加了count和query等方法。修改的具体内容如下：

1、API基于luajit-2.0开发，相当于lua 5.1，需要使用lua-compat-5.2兼容lua 5.2

2、使用ngx.socket.tcp替换mongo.socket模块

3、增加了count，query，auth等方法

修改之后的代码见： [ lua-mongo ][lua-mongo]

具体的操作MongoDB的lua代码如下：

复制代码 代码如下:

\-- lua mongo test script  
\-- utils  
function string:split(sep)  
local sep, fields = sep or ":", \{\}  
local pattern = string.format("(\[^%s\]+)", sep)  
self:gsub(pattern, function(c) fields\[\#fields + 1\] = c end)  
return fields  
end  
\-- 常量  
HOST = "127.0.0.1"  
PORT = 27017  
KEEPALIVE\_TIMEOUT = 60000  
KEEPALIVE\_SIZE = 100  
CONN\_TIMEOUT = 3000  
DB\_USER = "user"  
DB\_PASSWD = "password"  
DB\_NAME = "blog"  
DB\_COLLECTION = "article"  
\-- 引用  
mongo = require("mongo")  
cjson = require("cjson.safe")  
cbson = require("bson")  
\-- 状态  
local status\_msg = "error"  
local status\_code = 500  
local message = "unknown error"  
local mongo\_query = \{\["category\_id"\] = \{\["$in"\] = \{1,2,3,4\}\}, \["status"\] = \{\["$ne"\] = 2\}, \["create\_time"\] = \{\["$lte"\] = 1427102260\}\}  
local mongo\_sort = \{\["create\_time"\] = 1\}  
local mongo\_limit = 100  
local mongo\_skip = 0  
local mongo\_fields = \{ \["\_id"\] = false \}  
\-- 涉及到时间的字段，需要使用bson转化一下  
if mongo\_query\["create\_time"\] then  
local create\_time = mongo\_query\["create\_time"\]  
local t = type(create\_time)  
if t == "table" then  
for key, value in pairs(create\_time) do  
mongo\_query\["create\_time"\]\[key\] = cbson.date(value)  
end  
else  
mongo\_query\["create\_time"\] = cbson.date(create\_time)  
end  
end  
local conn = mongo.client(\{ host = HOST, port = PORT \})  
conn:set\_timeout(CONN\_TIMEOUT)  
local db = conn:getDB(DB\_NAME)  
local reused\_times = conn:get\_reused\_times()  
if reused\_times == 0 then  
db:auth(DB\_USER, DB\_PASSWD)  
end  
local col = db:getCollection(DB\_COLLECTION)  
local result = \{\}  
\-- count  
local count, err = col:count(mongo\_query)  
local ok, err = conn:set\_keepalive(KEEPALIVE\_TIMEOUT, KEEPALIVE\_SIZE)  
if count ~= nil then  
result = count  
status\_code = 200  
status\_msg = "ok"  
message = "success"  
end  
\-- query  
local bson\_obj  
if mongo\_sort then  
bson\_obj = cbson.encode\_order("$query", mongo\_query, "$orderby", mongo\_sort)  
else  
bson\_obj = cbson.encode(\{ \["$query"\] = mongo\_query \})  
end  
local results = col:query(bson\_obj, mongo\_fields, mongo\_skip, mongo\_limit)  
local ok, err = conn:set\_keepalive(KEEPALIVE\_TIMEOUT, KEEPALIVE\_SIZE)  
if results then  
for \_, object in pairs(results) do  
for key, value in pairs(object) do  
if value == cbson.null then  
object\[key\] = cjson.null  
else  
local type\_name, value = cbson.type(value)  
object\[key\] = value  
end  
end  
end  
result = results  
status\_code = 200  
status\_msg = "ok"  
message = "success"  
end  
\-- findOne  
local results = col:findOne(\{\["id"\] = 14 \})  
local ok, err = conn:set\_keepalive(KEEPALIVE\_TIMEOUT, KEEPALIVE\_SIZE)  
if results then  
for key, value in pairs(results) do  
if value == cbson.null then  
results\[key\] = cjson.null  
else  
local type\_name, value = cbson.type(value)  
results\[key\] = value  
end  
end  
result = results  
status\_code = 200  
status\_msg = "ok"  
message = "success"  
end  
ngx.status = status\_code  
json\_out = cjson.encode(\{ status = status\_msg, message = message, data = result \})  
ngx.header\["Content-Length"\] = json\_out:len()  
ngx.print(json\_out)

来源:http://www.jb51.net/article/62871.htm

[lua-mongo]: https://github.com/WuXianglong/lua-mongo