# HG changeset patch
# User wenzelm
# Date 1688560393 -7200
# Node ID 12d54a78bc0eda2f806a6408c69ed8bc85ba7b97
# Parent  4dca4ba6f01b1c805c8d476d9113f103af5a5eba
more robust;

diff -r 4dca4ba6f01b -r 12d54a78bc0e src/Pure/General/sql.scala
--- a/src/Pure/General/sql.scala	Wed Jul 05 13:41:45 2023 +0200
+++ b/src/Pure/General/sql.scala	Wed Jul 05 14:33:13 2023 +0200
@@ -642,7 +642,7 @@
     // see https://www.postgresql.org/docs/current/explicit-locking.html
 
     override def lock_tables(tables: List[SQL.Table]): PostgreSQL.Source =
-      "LOCK TABLE " + tables.mkString(", ") + " IN ACCESS EXCLUSIVE MODE"
+      if_proper(tables, "LOCK TABLE " + tables.mkString(", ") + " IN ACCESS EXCLUSIVE MODE")
 
 
     /* notifications: IPC via database server */