fix orphans

internal/backend/db.go

@@ -102,7 +102,7 @@ func (b *DBBackend) initSchema(ctx context.Context) error {
 		)`,
 		`CREATE TABLE IF NOT EXISTS calendar_objects (
 		    id SERIAL PRIMARY KEY,
-		    calendar_id INTEGER REFERENCES calendars(id) ON DELETE CASCADE,
+		    calendar_id INTEGER NOT NULL REFERENCES calendars(id) ON DELETE CASCADE,
 		    path TEXT NOT NULL,
 		    data TEXT NOT NULL,
 		    etag TEXT NOT NULL,
@@ -110,20 +110,20 @@ func (b *DBBackend) initSchema(ctx context.Context) error {
 		)`,
 		`CREATE TABLE IF NOT EXISTS addressbooks (
 		    id SERIAL PRIMARY KEY,
-		    owner_id INTEGER REFERENCES users(id) ON DELETE CASCADE,
+		    owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
 		    path TEXT UNIQUE NOT NULL,
 		    name TEXT,
 		    description TEXT
 		)`,
 		`CREATE TABLE IF NOT EXISTS addressbook_access (
-		    addressbook_id INTEGER REFERENCES addressbooks(id) ON DELETE CASCADE,
-		    user_id INTEGER REFERENCES users(id) ON DELETE CASCADE,
+		    addressbook_id INTEGER NOT NULL REFERENCES addressbooks(id) ON DELETE CASCADE,
+		    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
 		    mode TEXT NOT NULL,
 		    PRIMARY KEY (addressbook_id, user_id)
 		)`,
 		`CREATE TABLE IF NOT EXISTS addressbook_objects (
 		    id SERIAL PRIMARY KEY,
-		    addressbook_id INTEGER REFERENCES addressbooks(id) ON DELETE CASCADE,
+		    addressbook_id INTEGER NOT NULL REFERENCES addressbooks(id) ON DELETE CASCADE,
 		    path TEXT NOT NULL,
 		    data TEXT NOT NULL,
 		    etag TEXT NOT NULL,