I dont use mysql-async and would advise making the switch to OxMySQL.
but in your example you can do something like
MySQL.ready(function()
local p = promise.new()
MySQL.Async.fetchAll("SELECT * FROM mytable WHERE id = @id", { ["@id"] = id }, function(result)
p:resolve(result)
end)
local result = Citizen.Await(p)
if result[1] then
print("sucess")
local username = result[1].username
print("username", username)
else
print("no user found")
end
end)