local skynet = require "skynet"
  local mysqlproxy = require "shared.mysqlproxy"
  
  
  function getDbCfgVal(tbName, keyName, fieldName)
      local sql = string.format("SELECT * FROM `%s` WHERE `key` = '%s';", tbName, keyName)
      local res = mysqlproxy:query(sql)
      if not next(res) or res.errno then
          return
      end
  
      return res[1][fieldName]
  end
  
  function setDbCfgVal(tbName, keyName, fieldName, fieldVal)
      if type(fieldVal) == "string" then fieldVal = string.format("'%s'", fieldVal) end
      local sql = string.format("UPDATE `%s` SET `%s` = %s WHERE `key` = '%s';", tbName, fieldName, fieldVal, keyName)
      mysqlproxy:query(sql)
  end