Support triggers on views.

This patch adds the SQL-standard concept of an INSTEAD OF trigger, which
is fired instead of performing a physical insert/update/delete.  The
trigger function is passed the entire old and/or new rows of the view,
and must figure out what to do to the underlying tables to implement
the update.  So this feature can be used to implement updatable views
using trigger programming style rather than rule hacking.

In passing, this patch corrects the names of some columns in the
information_schema.triggers view.  It seems the SQL committee renamed
them somewhere between SQL:99 and SQL:2003.

Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/pl/plpython/sql/plpython_trigger.sql b/src/pl/plpython/sql/plpython_trigger.sql
index c60a673780..c3af5c211e 100644
--- a/src/pl/plpython/sql/plpython_trigger.sql
+++ b/src/pl/plpython/sql/plpython_trigger.sql
@@ -99,7 +99,24 @@ update trigger_test set v = 'update' where i = 1;
 delete from trigger_test;
 truncate table trigger_test;
 
+DROP TRIGGER show_trigger_data_trig_stmt on trigger_test;
+DROP TRIGGER show_trigger_data_trig_before on trigger_test;
+DROP TRIGGER show_trigger_data_trig_after on trigger_test;
+
+insert into trigger_test values(1,'insert');
+CREATE VIEW trigger_test_view AS SELECT * FROM trigger_test;
+
+CREATE TRIGGER show_trigger_data_trig
+INSTEAD OF INSERT OR UPDATE OR DELETE ON trigger_test_view
+FOR EACH ROW EXECUTE PROCEDURE trigger_data(24,'skidoo view');
+
+insert into trigger_test_view values(2,'insert');
+update trigger_test_view set v = 'update' where i = 1;
+delete from trigger_test_view;
+
 DROP FUNCTION trigger_data() CASCADE;
+DROP VIEW trigger_test_view;
+delete from trigger_test;
 
 
 --