For example, if my smart contract holds very basic detail of a patient and I want to access his / her medical report stored in a database (mongoDB) .

  • Do you want your contract to access the database and get data to use inside its business logic? Commented Nov 24, 2017 at 11:04
  • Yes @ Luiz Soares Commented Nov 24, 2017 at 11:36

1 Answer 1


To do that, you are going to need a service like Oraclizeit. You may find a rough explanation about it here: How Oraclize and API call works

And if you use Oraclizeit and it returns to your contract a big amount of data, you may explode your gas amount and won´t be able to execute your function. You should take that in count.

You can´t make a direct connection between your contract and mongoDB. Contracts must be atomic.


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