# Trait ethcore::trace::DatabaseExtras [−] [src]

    pub trait DatabaseExtras {
        fn block_hash(&self, block_number: BlockNumber) -> Option<H256>;
        fn transaction_hash(&self,
                        block_number: BlockNumber,
                        tx_position: usize)
                        -> Option<H256>;
    }

`DbExtras` provides an interface to query extra data which is not stored in tracesdb, but necessary to work correctly.

## Required Methods

### `fn block_hash(&self, block_number: BlockNumber) -> Option<H256>`

Returns hash of given block number.

### `fn transaction_hash(&self,
block_number: BlockNumber,
tx_position: usize)
-> Option<H256>`

Returns hash of transaction at given position.

## Implementors

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