[#2171] eliminate duplicate DReps

CHANGELOG.md

@@ -16,7 +16,7 @@ changes.
 
 ### Fixed
 
--
+- Eliminate duplicate DReps in the DRep Directory [Issue 2171](https://github.com/IntersectMBO/govtool/issues/2171)
 
 ### Changed
 

govtool/backend/sql/list-dreps.sql

@@ -30,7 +30,7 @@ SELECT
   newestRegister.time AS last_register_time,
   COALESCE(latestDeposit.deposit, 0),
   non_deregister_voting_anchor.url IS NOT NULL AS has_non_deregister_voting_anchor,
-  off_chain_vote_fetch_error.fetch_error,
+  fetch_error.message,
   off_chain_vote_drep_data.payment_address,
   off_chain_vote_drep_data.given_name,
   off_chain_vote_drep_data.objectives,
@@ -96,8 +96,15 @@ FROM
   LEFT JOIN DRepDistr ON DRepDistr.hash_id = dh.id
     AND DRepDistr.rn = 1
   LEFT JOIN voting_anchor va ON va.id = dr_voting_anchor.voting_anchor_id
-  LEFT JOIN voting_anchor non_deregister_voting_anchor on non_deregister_voting_anchor.id = dr_non_deregister_voting_anchor.voting_anchor_id
-  LEFT JOIN off_chain_vote_fetch_error ON off_chain_vote_fetch_error.voting_anchor_id = va.id
+  LEFT JOIN voting_anchor non_deregister_voting_anchor ON non_deregister_voting_anchor.id = dr_non_deregister_voting_anchor.voting_anchor_id
+  LEFT JOIN (
+    SELECT fetch_error as message, voting_anchor_id
+    FROM off_chain_vote_fetch_error
+    WHERE fetch_time = (
+      SELECT max(fetch_time)
+      FROM off_chain_vote_fetch_error)
+    GROUP BY fetch_error, voting_anchor_id
+  ) AS fetch_error ON fetch_error.voting_anchor_id = va.id
   LEFT JOIN off_chain_vote_data ON off_chain_vote_data.voting_anchor_id = va.id
   LEFT JOIN off_chain_vote_drep_data on off_chain_vote_drep_data.off_chain_vote_data_id = off_chain_vote_data.id 
   CROSS JOIN DRepActivity
@@ -140,7 +147,7 @@ GROUP BY
   newestRegister.time,
   latestDeposit.deposit,
   non_deregister_voting_anchor.url,
-  off_chain_vote_fetch_error.fetch_error,
+  fetch_error.message,
   off_chain_vote_drep_data.payment_address,
   off_chain_vote_drep_data.given_name,
   off_chain_vote_drep_data.objectives,