Můžete to udělat pomocí dotazu:
select (case when city = 'mumbai' then 'pune'
when city = 'pune' then 'mumbai'
else city
end)
. . .
Pokud chcete změnit hodnoty, pak:
update table t
set city = (case when city = 'mumbai' then 'pune'
when city = 'pune' then 'mumbai'
end)
where city in ('mumbai', 'pune');