From d80f5ff5341fb1bd90618e4a9cc46c289f5d5541 Mon Sep 17 00:00:00 2001
From: damien DELPY <damien.delpy@bordeaux-inp.fr>
Date: Tue, 3 Dec 2024 11:52:49 +0100
Subject: [PATCH] feat: some triggers to update a note, remove a thread in
 cascade, and remove a piece in cascade.

---
 PostgreSQL/Makefile       |  2 +-
 PostgreSQL/src/create.sql | 63 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/PostgreSQL/Makefile b/PostgreSQL/Makefile
index fbc01d6..d594d2c 100644
--- a/PostgreSQL/Makefile
+++ b/PostgreSQL/Makefile
@@ -7,9 +7,9 @@ build: \
 	$(DIR_BUILD)/00_drop.sql \
 	$(DIR_BUILD)/01_create.sql \
 	$(DIR_BUILD)/02_insert.sql \
+	$(DIR_BUILD)/04_update.sql \
 	$(DIR_BUILD)/05_functions.sql
 	# $(DIR_BUILD)/03_select.sql \
-	# $(DIR_BUILD)/04_update.sql
 
 generate_data:
 	python3 generate_data.py
diff --git a/PostgreSQL/src/create.sql b/PostgreSQL/src/create.sql
index 3a1a9e7..937b401 100644
--- a/PostgreSQL/src/create.sql
+++ b/PostgreSQL/src/create.sql
@@ -384,3 +384,66 @@ CREATE OR REPLACE VIEW nb_modele_par_membre AS
   WHERE membres.id_membre IS NOT NULL
   GROUP BY membres.id_membre
 );
+
+-- ============================================================================
+-- Triggers.
+-- ============================================================================
+
+-- A noter should be between 0 and 5.
+CREATE OR REPLACE FUNCTION note_veryfier()
+RETURNS TRIGGER AS $$
+BEGIN
+    IF NEW.note_noter < 0 OR NEW.note_noter > 5 THEN
+        RAISE EXCEPTION 'You should give a note between 0 and 5';
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER note_veryfier
+BEFORE INSERT OR UPDATE ON noter
+FOR EACH ROW
+EXECUTE FUNCTION note_veryfier();
+
+-- To delete all the messages from a message thread.
+CREATE OR REPLACE FUNCTION delete_messages_after_thread()
+RETURNS TRIGGER AS $$
+BEGIN
+    DELETE FROM messages WHERE id_fil = OLD.id_fil;
+    RETURN OLD;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER delete_messages_after_thread
+AFTER DELETE ON fils
+FOR EACH ROW
+EXECUTE FUNCTION delete_messages_after_thread();
+
+-- To remove a piece and all its dependencies.
+CREATE OR REPLACE FUNCTION delete_cascade_piece()
+RETURNS TRIGGER AS $$
+BEGIN
+    -- If this is a complex piece.
+    DELETE FROM etre_complexe   WHERE id_piece = OLD.id_piece;
+
+    DELETE FROM colorer         WHERE id_piece = OLD.id_piece;
+    DELETE FROM avoir_motif     WHERE id_piece = OLD.id_piece;
+    DELETE FROM etre_forme      WHERE id_piece = OLD.id_piece;
+    DELETE FROM necessiter      WHERE id_piece = OLD.id_piece;
+    DELETE FROM acheter         WHERE id_piece = OLD.id_piece;
+    DELETE FROM perdre          WHERE id_piece = OLD.id_piece;
+    DELETE FROM contenir        WHERE id_piece = OLD.id_piece;
+    DELETE FROM etre            WHERE id_piece = OLD.id_piece;
+    DELETE FROM pieces          WHERE id_piece = OLD.id_piece;
+
+    return OLD;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER delete_cascade_piece
+AFTER DELETE ON pieces
+FOR EACH ROW
+EXECUTE FUNCTION delete_cascade_piece();
+
+-- ============================================================================
+