diff --git a/xuqm-bugcollect-service/src/main/resources/db/migration/V8__sourcemap_uk_add_build_id.sql b/xuqm-bugcollect-service/src/main/resources/db/migration/V8__sourcemap_uk_add_build_id.sql
new file mode 100644
index 0000000..3d4635b
--- /dev/null
+++ b/xuqm-bugcollect-service/src/main/resources/db/migration/V8__sourcemap_uk_add_build_id.sql
@@ -0,0 +1,14 @@
+-- V8: Include build_id in log_sourcemaps unique constraint.
+--
+-- Problem: uk_map was (app_key, platform, app_version, bundle_name).
+-- When the Gradle plugin uploads mapping files with a per-build buildId,
+-- each new build of the same version generates a different buildId and tries
+-- to INSERT a new row, which violates the old constraint → HTTP 500.
+--
+-- Fix: rebuild uk_map to include build_id.
+-- MySQL treats NULLs as distinct in unique indexes, so legacy records
+-- (build_id IS NULL) coexist without conflict. Application logic already
+-- prevents duplicate NULL-buildId rows via findByAppKeyAndPlatformAndAppVersionAndBuildIdIsNullAndBundleName.
+
+ALTER TABLE log_sourcemaps DROP INDEX uk_map;
+ALTER TABLE log_sourcemaps ADD UNIQUE KEY uk_map (app_key, platform, app_version, build_id, bundle_name);