ALTER TABLE question_bank
    ADD COLUMN IF NOT EXISTS topic VARCHAR(255) NULL AFTER difficulty,
    ADD COLUMN IF NOT EXISTS bloom_level VARCHAR(50) NULL AFTER topic,
    ADD COLUMN IF NOT EXISTS section_title VARCHAR(255) NULL AFTER bloom_level,
    ADD COLUMN IF NOT EXISTS source_exam_id INT(11) NULL AFTER section_title,
    ADD COLUMN IF NOT EXISTS source_material_ids TEXT NULL AFTER source_exam_id,
    ADD COLUMN IF NOT EXISTS question_hash VARCHAR(64) NULL AFTER source_material_ids,
    ADD INDEX IF NOT EXISTS idx_question_hash (question_hash);

