From 71e2ffbed322a260e162ad9bf9fe56ce638e7bbc Mon Sep 17 00:00:00 2001
From: Neeraj Kashyap <nkashy1@gmail.com>
Date: Tue, 21 Nov 2023 10:59:17 -0800
Subject: [PATCH] Modified alembic migration to downgrade properly

Previously, the downgrade was hitting a violation of the old unique
constraint on leaderboard_scores if multiple versions of scores were
stored for the same address.

The modified downgrade only retains the score for each address on the
latest publich version of each leaderboard.
---
 ...153_added_leaderboard_versions_table_and_.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/engineapi/alembic/versions/cc80e886e153_added_leaderboard_versions_table_and_.py b/engineapi/alembic/versions/cc80e886e153_added_leaderboard_versions_table_and_.py
index 515d638c..b6dff83e 100644
--- a/engineapi/alembic/versions/cc80e886e153_added_leaderboard_versions_table_and_.py
+++ b/engineapi/alembic/versions/cc80e886e153_added_leaderboard_versions_table_and_.py
@@ -105,6 +105,23 @@ def upgrade():
 
 
 def downgrade():
+    op.execute(
+        """
+        WITH latest_version_for_leaderboard AS (
+            SELECT leaderboard_id, MAX(version_number) AS latest_version
+            FROM leaderboard_versions WHERE published = true
+            GROUP BY leaderboard_id
+        )
+        DELETE FROM leaderboard_scores WHERE
+            (leaderboard_id, leaderboard_version_number) NOT IN (
+                SELECT
+                    leaderboard_id,
+                    latest_version AS leaderboard_version_number
+                FROM
+                    latest_version_for_leaderboard
+            )
+        """
+    )
     # ### commands auto generated by Alembic - please adjust! ###
     op.drop_constraint(
         op.f("fk_leaderboard_scores_leaderboard_id_leaderboard_versions"),