active listing constraint for bidding

migrations/02_add_bid_active_listing_constraint.sql

@@ -0,0 +1,15 @@
+-- Add constraint to prevent bids on inactive listings
+-- This ensures atomicity at the database level
+
+-- Create a trigger to prevent bids on inactive listings
+-- This is more reliable than CHECK constraints in SQLite
+CREATE TRIGGER prevent_bid_on_inactive_listing
+    BEFORE INSERT ON bids
+    FOR EACH ROW
+    WHEN (
+        SELECT COALESCE(is_active, 0) FROM listings WHERE id = NEW.listing_id
+    ) != 1
+BEGIN
+    SELECT RAISE(ABORT, 'Cannot place bid on inactive listing');
+END;
+