some online service like fxblue.com and signalstart.com
,you submit your mt4 account number,broker server and read-only password,and
then they could constantly and automatically extract your latest account
statement to their database,and analyse your statement with beautiful charts on
webpage.Could some tell how to make this? Is it a loop execute script running
on mt4 terminal? anyone could develop similar tools?
Those services use their own mechanisms, probably with tools provided by MetaQuotes to access your account data and extract the order history.
As for your own implementation, just access the Order History, either via an Expert Advisor or Script and output the data for processing externally, or have that code generate the statistics and/or graph in HTML directly itself.
For that you are going to have to learn how to code in MQL yourself!
PS! There are 3rd Party tools that accomplish such things, some of which use the standard MetaTrader report output to do it. Just search the web for such tools as we are not allowed to advertise here.