1 files changed, 12 insertions, 0 deletions
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 995114e405..61215bbc7b 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -487,3 +487,15 @@ def prepare_sqlite3_database(db_conn):
                     " VALUES (?,?)",
                     (row[0], False)
                 )
+
+
+def are_all_users_on_domain(txn, database_engine, domain):
+    sql = database_engine.convert_param_style(
+        "SELECT COUNT(*) FROM users WHERE name NOT LIKE ?"
+    )
+    pat = "%:" + domain
+    txn.execute(sql, (pat,))
+    num_not_matching = txn.fetchall()[0][0]
+    if num_not_matching == 0:
+        return True
+    return False