diff --git a/swh/core/cli/db.py b/swh/core/cli/db.py
--- a/swh/core/cli/db.py
+++ b/swh/core/cli/db.py
@@ -389,13 +389,19 @@
             f"{ds_version} of the datastore backend {db_module}"
         )
 
-    new_db_version = swh_db_upgrade(dbname, module, to_version)
-    click.secho(f"Migration to version {new_db_version} done", fg="green")
-    if new_db_version < ds_version:
+    if to_version == db_version:
         click.secho(
-            f"Warning: migration was not complete: the current version is {ds_version}",
-            fg="yellow",
+            f"No migration needed: the current version is {db_version}", fg="yellow",
         )
+    else:
+        new_db_version = swh_db_upgrade(dbname, module, to_version)
+        click.secho(f"Migration to version {new_db_version} done", fg="green")
+        if new_db_version < ds_version:
+            click.secho(
+                "Warning: migration was not complete: "
+                f"the current version is {ds_version}",
+                fg="yellow",
+            )
 
 
 def get_dburl_from_config(cfg):
diff --git a/swh/core/db/db_utils.py b/swh/core/db/db_utils.py
--- a/swh/core/db/db_utils.py
+++ b/swh/core/db/db_utils.py
@@ -11,7 +11,7 @@
 import pathlib
 import re
 import subprocess
-from typing import Collection, Dict, List, Optional, Tuple, Union
+from typing import Collection, Dict, List, Optional, Tuple, Union, cast
 
 import psycopg2
 import psycopg2.errors
@@ -143,7 +143,8 @@
             )
             try:
                 c.execute(query)
-                return c.fetchall()
+                versions = cast(List[Tuple[int, datetime, str]], c.fetchall())
+                return versions
             except psycopg2.errors.UndefinedTable:
                 return None
     except Exception:
@@ -185,6 +186,9 @@
         if db_version < int(fname.stem) <= to_version
     ]
 
+    if not sqlfiles:
+        return db_version
+
     for sqlfile in sqlfiles:
         new_version = int(path.splitext(path.basename(sqlfile))[0])
         logger.info("Executing migration script {sqlfile}")