diff --git a/src/main/resources/db/V1000_25__mai2_unique.sql b/src/main/resources/db/V1000_25__mai2_unique.sql
new file mode 100644
index 00000000..6b9bab91
--- /dev/null
+++ b/src/main/resources/db/V1000_25__mai2_unique.sql
@@ -0,0 +1,131 @@
+# Delete duplicate rows
+DELETE FROM maimai2_user_extend
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_extend
+    GROUP BY user_id
+);
+
+DELETE FROM maimai2_user_option
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_option
+    GROUP BY user_id
+);
+
+DELETE FROM maimai2_user_character
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_character
+    GROUP BY user_id, character_id
+);
+
+DELETE FROM maimai2_user_map
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_map
+    GROUP BY user_id, map_id
+);
+
+DELETE FROM maimai2_user_login_bonus
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_login_bonus
+    GROUP BY user_id, bonus_id
+);
+
+DELETE FROM maimai2_user_udemae
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_udemae
+    GROUP BY user_id
+);
+
+DELETE FROM maimai2_user_general_data
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_general_data
+    GROUP BY user_id, property_key
+);
+
+DELETE FROM maimai2_user_item
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_item
+    GROUP BY user_id, item_id, item_kind
+);
+
+DELETE FROM maimai2_user_music_detail
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_music_detail
+    GROUP BY user_id, music_id, level
+);
+
+DELETE FROM maimai2_user_course
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_course
+    GROUP BY user_id, course_id
+);
+
+DELETE FROM maimai2_user_friend_season_ranking
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_friend_season_ranking
+    GROUP BY user_id, season_id
+);
+
+DELETE FROM maimai2_user_favorite
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_favorite
+    GROUP BY user_id, item_kind
+);
+
+DELETE FROM maimai2_user_activity
+WHERE id NOT IN (
+    SELECT MAX(id)
+    FROM maimai2_user_activity
+    GROUP BY user_id, activity_id, kind
+);
+
+# Add unique constraint
+ALTER TABLE maimai2_user_extend
+    ADD CONSTRAINT unique_maimai2_user_extend UNIQUE (user_id);
+
+ALTER TABLE maimai2_user_option
+    ADD CONSTRAINT unique_maimai2_user_option UNIQUE (user_id);
+
+ALTER TABLE maimai2_user_character
+    ADD CONSTRAINT unique_maimai2_user_character UNIQUE (user_id, character_id);
+
+ALTER TABLE maimai2_user_map
+    ADD CONSTRAINT unique_maimai2_user_map UNIQUE (user_id, map_id);
+
+ALTER TABLE maimai2_user_login_bonus
+    ADD CONSTRAINT unique_maimai2_user_login_bonus UNIQUE (user_id, bonus_id);
+
+ALTER TABLE maimai2_user_udemae
+    ADD CONSTRAINT unique_maimai2_user_udemae UNIQUE (user_id);
+
+ALTER TABLE maimai2_user_general_data
+    ADD CONSTRAINT unique_maimai2_user_general_data UNIQUE (user_id, property_key);
+
+ALTER TABLE maimai2_user_item
+    ADD CONSTRAINT unique_maimai2_user_item UNIQUE (user_id, item_id, item_kind);
+
+ALTER TABLE maimai2_user_music_detail
+    ADD CONSTRAINT unique_maimai2_user_music_detail UNIQUE (user_id, music_id, level);
+
+ALTER TABLE maimai2_user_course
+    ADD CONSTRAINT unique_maimai2_user_course UNIQUE (user_id, course_id);
+
+ALTER TABLE maimai2_user_friend_season_ranking
+    ADD CONSTRAINT unique_maimai2_user_friend_season_ranking UNIQUE (user_id, season_id);
+
+ALTER TABLE maimai2_user_favorite
+    ADD CONSTRAINT unique_maimai2_user_favorite UNIQUE (user_id, item_kind);
+
+ALTER TABLE maimai2_user_activity
+    ADD CONSTRAINT unique_maimai2_user_activity UNIQUE (user_id, activity_id, kind);