silently discard insert

src/data_access_layer/migrations/059_node_insert_trigger_rewrite.sql

@@ -0,0 +1,32 @@
+CREATE OR REPLACE FUNCTION node_insert_trigger() RETURNS TRIGGER AS $$
+DECLARE
+    old_id bigint;
+    old_properties jsonb;
+BEGIN
+    IF NEW.original_data_id IS NOT NULL THEN
+        BEGIN
+            SELECT nodes.id, nodes.properties
+            INTO old_id, old_properties
+            FROM nodes
+            WHERE original_data_id = NEW.original_data_id
+              AND metatype_id = NEW.metatype_id
+              AND data_source_id = NEW.data_source_id LIMIT 1;
+        EXCEPTION
+            WHEN NO_DATA_FOUND THEN
+                old_id := NULL;
+        END;
+
+        IF old_id IS NOT NULL THEN
+            NEW.id = old_id;
+/*
+ if the old properties are exactly the same as the new properties, silently discard the insert
+ */
+            IF old_properties IS NOT DISTINCT FROM NEW.properties THEN
+                RETURN NULL;
+            END IF;
+        END IF;
+    END IF;
+
+    RETURN NEW;
+END;
+$$ language plpgsql;