From 3fff973ab6d4b6cb1b384dabadd9b5bc451183cb Mon Sep 17 00:00:00 2001
From: Deluan <deluan@navidrome.org>
Date: Mon, 20 Jul 2026 08:41:04 -0400
Subject: [PATCH] refactor(db): apply review feedback to id migration

Filter empty strings in collectColumn's SQL, reuse a prepared statement
for rewriteColumn updates, and clarify the legacy ID functions' comment
now that they emit the canonical encoding.
---
 .../20260720015443_uniform_canonical_ids.go         | 13 ++++++++++---
 model/metadata/legacy_ids.go                        |  4 ++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/db/migrations/20260720015443_uniform_canonical_ids.go b/db/migrations/20260720015443_uniform_canonical_ids.go
index a0fdd9e4d..4f987e108 100644
--- a/db/migrations/20260720015443_uniform_canonical_ids.go
+++ b/db/migrations/20260720015443_uniform_canonical_ids.go
@@ -98,7 +98,7 @@ func buildIDMap(ctx context.Context, tx *sql.Tx) error {
 
 func collectColumn(ctx context.Context, tx *sql.Tx, ins *sql.Stmt, table, col string) error {
 	rows, err := tx.QueryContext(ctx, fmt.Sprintf(
-		"SELECT DISTINCT %[2]s FROM %[1]s WHERE %[2]s IS NOT NULL", table, col))
+		"SELECT DISTINCT %[2]s FROM %[1]s WHERE %[2]s IS NOT NULL AND %[2]s <> ''", table, col))
 	if err != nil {
 		return err
 	}
@@ -168,9 +168,16 @@ func rewriteColumn(ctx context.Context, tx *sql.Tx, table, col string, transform
 		return err
 	}
 	_ = rows.Close()
+	if len(changes) == 0 {
+		return nil
+	}
+	upd, err := tx.PrepareContext(ctx, fmt.Sprintf("UPDATE %s SET %s = ? WHERE rowid = ?", table, col))
+	if err != nil {
+		return err
+	}
+	defer upd.Close()
 	for _, c := range changes {
-		if _, err := tx.ExecContext(ctx, fmt.Sprintf(
-			"UPDATE %s SET %s = ? WHERE rowid = ?", table, col), c.val, c.rowid); err != nil {
+		if _, err := upd.ExecContext(ctx, c.val, c.rowid); err != nil {
 			return err
 		}
 	}
diff --git a/model/metadata/legacy_ids.go b/model/metadata/legacy_ids.go
index 57c367b44..0c1d5825a 100644
--- a/model/metadata/legacy_ids.go
+++ b/model/metadata/legacy_ids.go
@@ -12,8 +12,8 @@ import (
 	"github.com/navidrome/navidrome/model/id"
 )
 
-// These are the legacy ID functions that were used in the original Navidrome ID generation.
-// They are kept here for backwards compatibility with existing databases.
+// These legacy ID functions hash the same inputs as the original Navidrome ID generation,
+// now emitted in the canonical base62 encoding (matching what the uniform-ids migration stores).
 
 func legacyTrackID(mf model.MediaFile, prependLibId bool) string {
 	key := mf.Path