case

when b.block_number < 15537351 then 'Before Merge'

when b.block_number >= 15537351 then 'After Merge'

end as merge,

avg (a.price) as ETH_Price

from ethereum.core.fact_hourly_token_prices a join ethereum.core.fact_transactions b on a.HOUR::date=b.BLOCK_TIMESTAMP::date

where a.symbol = 'WETH'

and a.HOUR::date>='2022-09-01'

group by 1