From d2828310f240aed098e5b3d787f5d63f47575a7a Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Thu, 28 Dec 2023 11:12:20 +0100
Subject: [PATCH] Modify DELETE triggers to delete BEFORE instead of AFTER to
 prevent possible foreign key constraint violations

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 .../Scripts/database_migration/gravity-db.sh  |  7 +++++
 .../database_migration/gravity/18_to_19.sql   | 27 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 advanced/Scripts/database_migration/gravity/18_to_19.sql

diff --git a/advanced/Scripts/database_migration/gravity-db.sh b/advanced/Scripts/database_migration/gravity-db.sh
index 7b356b3a..e99f1df2 100755
--- a/advanced/Scripts/database_migration/gravity-db.sh
+++ b/advanced/Scripts/database_migration/gravity-db.sh
@@ -152,4 +152,11 @@ upgrade_gravityDB(){
 		pihole-FTL sqlite3 -ni "${database}" < "${scriptPath}/17_to_18.sql"
 		version=18
 	fi
+	if [[ "$version" == "18" ]]; then
+		# Modify DELETE triggers to delete BEFORE instead of AFTER to prevent
+		# foreign key constraint violations
+		echo -e "  ${INFO} Upgrading gravity database from version 18 to 19"
+		pihole-FTL sqlite3 -ni "${database}" < "${scriptPath}/18_to_19.sql"
+		version=19
+	fi
 }
diff --git a/advanced/Scripts/database_migration/gravity/18_to_19.sql b/advanced/Scripts/database_migration/gravity/18_to_19.sql
new file mode 100644
index 00000000..c85a4d57
--- /dev/null
+++ b/advanced/Scripts/database_migration/gravity/18_to_19.sql
@@ -0,0 +1,27 @@
+.timeout 30000
+
+PRAGMA FOREIGN_KEYS=OFF;
+
+BEGIN TRANSACTION;
+
+DROP TRIGGER tr_domainlist_delete;
+CREATE TRIGGER tr_domainlist_delete BEFORE DELETE ON domainlist
+    BEGIN
+      DELETE FROM domainlist_by_group WHERE domainlist_id = OLD.id;
+    END;
+
+DROP TRIGGER tr_adlist_delete;
+CREATE TRIGGER tr_adlist_delete BEFORE DELETE ON adlist
+    BEGIN
+      DELETE FROM adlist_by_group WHERE adlist_id = OLD.id;
+    END;
+
+DROP TRIGGER tr_client_delete;
+CREATE TRIGGER tr_client_delete BEFORE DELETE ON client
+    BEGIN
+      DELETE FROM client_by_group WHERE client_id = OLD.id;
+    END;
+
+UPDATE info SET value = 19 WHERE property = 'version';
+
+COMMIT;