diff -r b7b777fc916c -r 2fdf3d8a94e6 src/Pure/General/sql.scala
--- a/src/Pure/General/sql.scala	Wed Jun 07 17:09:17 2023 +0200
+++ b/src/Pure/General/sql.scala	Thu Jun 08 14:45:31 2023 +0200
@@ -152,6 +152,8 @@
     def where_equal(s: String): Source = SQL.where(equal(s))
     def where_member(set: Iterable[String]): Source = SQL.where(member(set))
 
+    def max: Column = copy(expr = "MAX(" + ident + ")")
+
     override def toString: Source = ident
   }