Get all ERC-20() transactions using BigQuery public dataset

get_all_erc_20_approve_transactions_using_bigquery.sql

-- Get all approve() transaction
--  Web3.utils.keccak256("approve(address,uint256)").slice(0, 10);
-- '0x095ea7b3'
WITH txdata as (
    SELECT tx.hash as txid, tx.block_timestamp as block_timestamp, cast(tx.receipt_gas_used as numeric) * cast(tx.gas_price as numeric) as cost FROM
        bigquery-public-data.crypto_ethereum.transactions as tx
    where 
        tx.input 
    LIKE  "0x095ea7b3%") 
SELECT (SUM(cost) / POWER(10, 18)) as eth_cost from txdata;

-- Verify Google data is good.
-- Get the last approve() transaction in Google dataset.
-- Check txid on Etherscan and should be around 5 minutes ago.
WITH txdata as (
    SELECT tx.hash as txid, tx.block_timestamp as block_timestamp, cast(tx.receipt_gas_used as numeric) * cast(tx.gas_price as numeric) as cost FROM
        bigquery-public-data.crypto_ethereum.transactions as tx
    where 
        tx.input 
    LIKE  "0x095ea7b3%") 
SELECT txid as last_txid FROM txdata ORDER BY block_timestamp DESC LIMIT 1;