Latest News

Ethereum: Why is it possible to have multiples addresses in an output of a transaction?

Understanding Ethereum Transaction Output and Address Plurality

As you’re trying to load your Ethereum blockchain into a MySQL database, it’s essential to grasp how Ethereum transactions are structured, particularly when it comes to output values. In this article, we’ll delve into why Ethereum allows for multiple addresses in an output of a transaction and explore the implications for data storage.

Transaction Outputs

An Ethereum transaction typically has a single input (also known as a from address) and one or more outputs (also known as to addresses). Each output value is associated with a unique address, which can be either a private key or a public address. When you send funds from an input to multiple outputs, each output value receives the corresponding amount of Ether.

The Problem: Multiple Addresses in a Single Transaction

In Ethereum, there are cases where it’s possible to have multiple addresses within the same transaction output. This is known as having “multiple addresses” or “nested addresses.” To address this, the Ethereum protocol uses a mechanism called “address encoding,” which allows for multiple addresses to be stored together.

When you create a new Ethereum account, your public address is an example of such an encoding. If you have multiple accounts with different public addresses (e.g., 0x... and 0x...), they can both exist in the same transaction output, even though they’re separate inputs.

MySQL Database Considerations

To load your Ethereum blockchain into a MySQL database, you’ll need to convert the raw transaction data from Ethereum’s JSON-LD format (the standard for representing Ethereum transactions) into a more manageable format. When doing so, you may encounter issues with storing and querying multiple addresses in a single output.

Address Plurality

In MySQL, table columns can only have a specific number of values; each value must be distinct from the others. However, when storing Ethereum transaction outputs with multiple addresses (e.g., 0x..., 0x..., and 0x...), you’re essentially creating a single column that stores three separate address strings.

To work around this limitation, MySQL supports “table variables” or “temporary tables,” which allow you to store values in a single column with multiple rows. You can create a temporary table using the CREATE TABLE statement and populate it with your Ethereum transaction data:

-- Create a temporary table to store Ethereum output addresses

CREATE TEMPORARY TABLE ethereum_outputs (

  address VARCHAR(42), -- Assuming 42 character limit per address

  value DECIMAL(8, 5)  // Store Ether amounts in decimal format

);


-- Insert Ethereum transaction data into the temporary table

INSERT INTO ethereum_outputs (address, value)

SELECT 

  '0x...', 

  '0x...',

  '0x...'

FROM your_transaction_data;


-- Query the temporary table to access multiple addresses in a single output

SELECT address, value FROMethereum_outputs WHERE address IN ('0x...', '0x...');

Keep in mind that this approach assumes you’re using MySQL version 8.0 or later, which supports CREATE TEMPORARY TABLE and the IN clause for querying.

Conclusion

In summary, Ethereum allows multiple addresses within a single transaction output due to address encoding. To load your Ethereum blockchain into a MySQL database, you can create temporary tables with separate columns for each address in the transaction outputs. By using table variables or stored procedures, you can efficiently store and query this data while avoiding limitations on addressing columns.

I hope this article has helped clarify the concept of multiple addresses in an Ethereum transaction output and provided guidance on how to work around MySQL’s addressing column constraints.