Openresrt最佳案例第6篇：OpenResty连接Mysql

Centos系统下安装mysql，先下载mysql-community-release-el7-5.noarch.rpm，然后通过yum安装，安装过程一直确定【Y】即可。

cd /usr/downloads/

wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm

rpm -ivh mysql-community-release-el7-5.noarch.rpm

yum install mysql-community-server

安装成功后，重启mysql，并进入mysql数据库，给root用户设置一个密码，密码为“123”。

service mysqld restart

mysql -u root -p

set password for root@localhost = password('123'); 

openresty连接mysql

lua-resty-mysql模块的官方文档地址： https://github.com/openresty/lua-resty-mysql

lua-resty-mysql – Lua MySQL client driver for ngx_lua based on the cosocket API

lua-resty-mysql模块是基于cosocket API 为ngx_lua提供的一个Lua MySQL客户端。它保证了100%非阻塞。

vim /usr/example/lua/test_mysql.lua，添加以下的代码：

local function close_db(db)  
    if not db then  
        return  
    end  
    db:close()  
end  

local mysql = require("resty.mysql")  

local db, err = mysql:new()  
if not db then  
    ngx.say("new mysql error : ", err)  
    return  
end  

db:set_timeout(1000)  

local props = {  
    host = "127.0.0.1",  
    port = 3306,  
    database = "mysql",  
    user = "root",  
    password = "123"  
}  

local res, err, errno, sqlstate = db:connect(props)  

if not res then  
   ngx.say("connect to mysql error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  

local drop_table_sql = "drop table if exists test"  
res, err, errno, sqlstate = db:query(drop_table_sql)  
if not res then  
   ngx.say("drop table error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  


local create_table_sql = "create table test(id int primary key auto_increment, ch varchar(100))"  
res, err, errno, sqlstate = db:query(create_table_sql)  
if not res then  
   ngx.say("create table error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  


local insert_sql = "insert into test (ch) values('hello')"  
res, err, errno, sqlstate = db:query(insert_sql)  
if not res then  
   ngx.say("insert error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  

res, err, errno, sqlstate = db:query(insert_sql)  

ngx.say("insert rows : ", res.affected_rows, " , id : ", res.insert_id, "<br/>")  


local update_sql = "update test set ch = 'hello2' where id =" .. res.insert_id  
res, err, errno, sqlstate = db:query(update_sql)  
if not res then  
   ngx.say("update error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  

ngx.say("update rows : ", res.affected_rows, "<br/>")  

local select_sql = "select id, ch from test"  
res, err, errno, sqlstate = db:query(select_sql)  
if not res then  
   ngx.say("select error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  


for i, row in ipairs(res) do  
   for name, value in pairs(row) do  
     ngx.say("select row ", i, " : ", name, " = ", value, "<br/>")  
   end  
end  

ngx.say("<br/>")  

local ch_param = ngx.req.get_uri_args()["ch"] or ''  

local query_sql = "select id, ch from test where ch = " .. ngx.quote_sql_str(ch_param)  
res, err, errno, sqlstate = db:query(query_sql)  
if not res then  
   ngx.say("select error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  

for i, row in ipairs(res) do  
   for name, value in pairs(row) do  
     ngx.say("select row ", i, " : ", name, " = ", value, "<br/>")  
   end  
end  


local delete_sql = "delete from test"  
res, err, errno, sqlstate = db:query(delete_sql)  
if not res then  
   ngx.say("delete error : ", err, " , errno : ", errno, " , sqlstate : ", sqlstate)  
   return close_db(db)  
end  

ngx.say("delete rows : ", res.affected_rows, "<br/>")  


close_db(db)  

在上面的代码中，展示了基本的创表、插入数据、修改数据、查询数据、删除数据的一些功能。

其中用到的lua-resty-mysql的一些API方法：

• syntax: db, err = mysql:new() 创建一个mysql数据库连接对象
• syntax: ok, err = db:connect(options) 尝试远程连接mysql
  • host mysql的主机名
  • port 端口
  • database 数据库名
  • user 用户名
  • password 密码
  • charset 编码
• syntax: db:set_timeout(time) 设置数据库连接超时时间
• syntax: ok, err = db:set_keepalive(max_idle_timeout, pool_size) 设置连接池
• syntax: ok, err = db:close() 关闭数据库
• syntax: bytes, err = db:send_query(query) 发送查询

lua-resty-mysql的一些关键的API方法，见https://github.com/openresty/lua-resty-mysql#table-of-contents

vim /usr/example/example.conf 在配置文件配置：

location /lua_mysql {
   default_type 'text/html';
   lua_code_cache on;
   content_by_lua_file /usr/example/lua/test_mysql.lua;
 }

浏览器访问http://116.196.177.123/lua_mysql，浏览器显示以下的内容：

insert rows : 1 , id : 2
update rows : 1
select row 1 : ch = hello
select row 1 : id = 1
select row 2 : ch = hello2
select row 2 : id = 2

delete rows : 2