fix(#1960): make calculation of the DRep voting power on the backend

Author: MSzalowski

CHANGELOG.md

@@ -26,6 +26,7 @@ changes.
 
 - Bumped Cardano node version to `10.1.0-pre`.
 - Bumped Cardano DB Sync version to `13.6.0.0-pre`.
+- Make calculation of a DRep voting power on the backend [Issue 1960](https://github.com/IntersectMBO/govtool/issues/1960)
 
 ### Removed
 

govtool/backend/sql/get-voting-power.sql

@@ -1,7 +1,6 @@
-select coalesce(drep_distr.amount, 0) as amount
-from drep_hash
-left join drep_distr
-on drep_hash.id = drep_distr.hash_id
-where drep_hash.raw = decode(?,'hex')
-order by epoch_no desc
-limit 1
+select sum(uv.value) as amount
+from utxo_view uv
+join delegation_vote dv on uv.stake_address_id = dv.addr_id
+join drep_hash dh on dv.drep_hash_id = dh.id
+where dh.raw = decode(?,'hex')
+and dv.cert_index != 0