Fixed foreign key text/reference in "common queries" section.

Docs/manual.texi

@@ -14909,10 +14909,14 @@ select * from shop where price=@@min_price or price=@@max_price;
 @cindex foreign keys
 @cindex keys, foreign
 
-You don't need foreign keys to join 2 tables.
+In MySQL 3.23.44 and up, @code{InnoDB} tables supports checking of
+foreign key constraints. @xref{InnoDB}.
+See also @ref{example-Foreign keys}.
 
-The only thing MySQL doesn't do is @code{CHECK} to make sure that
-the keys you use really exist in the table(s) you're referencing and it
+You don't actually need foreign keys to join 2 tables.
+The only thing MySQL currently doesn't do (in type types other than
+@code{InnoDB}), is @code{CHECK} to make sure that the keys you use
+really exist in the table(s) you're referencing and it
 doesn't automatically delete rows from a table with a foreign key
 definition. If you use your keys like normal, it'll work just fine: