-- Fix foreign key constraints on model_versions table to allow CASCADE delete

-- Drop existing constraints
ALTER TABLE model_versions DROP CONSTRAINT IF EXISTS model_versions_dataset_id_fkey;
ALTER TABLE model_versions DROP CONSTRAINT IF EXISTS model_versions_task_id_fkey;

-- Add constraints with ON DELETE SET NULL
ALTER TABLE model_versions
ADD CONSTRAINT model_versions_dataset_id_fkey
FOREIGN KEY (dataset_id) REFERENCES training_datasets(dataset_id) ON DELETE SET NULL;

ALTER TABLE model_versions
ADD CONSTRAINT model_versions_task_id_fkey
FOREIGN KEY (task_id) REFERENCES training_tasks(task_id) ON DELETE SET NULL;