Clarify wording of foreign key documentation to mention null entries as

not matching the primary key.

Report from Marek.Balgar@seznam.cz

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index c624fc2d9a23cb7c9d804384aa9f9acdd571a973..ea840fb8468f7d1d65b572d9880d74dd0178e143 100644 (file)
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -688,7 +688,7 @@ CREATE TABLE orders (
     quantity integer
 );
 </programlisting>
-    Now it is impossible to create orders with
+    Now it is impossible to create orders with non-NULL
     <structfield>product_no</structfield> entries that do not appear in the
     products table.
    </para>