esx_core/server/classes/datastore.lua

function stringsplit(inputstr, sep)
  if sep == nil then
    sep = "%s"
  end
  local t={} ; i=1
  for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
    t[i] = str
    i = i + 1
  end
  return t
end

function CreateDataStore(name, owner, data)

  local self = {}

  self.name  = name
  self.owner = owner
  self.data  = data

  local timeoutCallbacks = {}

  self.set = function(key, val)
    data[key] = val
    self.save()
  end

  self.get = function(key, i)

    local path = stringsplit(key, '.')
    local obj  = self.data

    for i=1, #path, 1 do
      obj = obj[path[i]]
    end

    if i == nil then
      return obj
    else
      return obj[i]
    end

  end

  self.count = function(key, i)

    local path = stringsplit(key, '.')
    local obj  = self.data

    for i=1, #path, 1 do
      obj = obj[path[i]]
    end

    if i ~= nil then
      obj = obj[i]
    end

    if obj == nil then
      return 0
    else
      return #obj
    end

  end

  self.save = function()

    for i=1, #timeoutCallbacks, 1 do
      ESX.ClearTimeout(timeoutCallbacks[i])
      timeoutCallbacks[i] = nil
    end

    local timeoutCallback = ESX.SetTimeout(10000, function()

      if self.owner == nil then
        MySQL.Async.execute(
          'UPDATE datastore_data SET data = @data WHERE name = @name',
          {
            ['@data'] = json.encode(self.data),
            ['@name'] = self.name,
          }
        )
      else
        MySQL.Async.execute(
          'UPDATE datastore_data SET data = @data WHERE name = @name and owner = @owner',
          {
            ['@data']  = json.encode(self.data),
            ['@name']  = self.name,
            ['@owner'] = self.owner,
          }
        )
      end

    end)

    table.insert(timeoutCallbacks, timeoutCallback)

  end

  return self

end