ALTER TABLE buildings DROP COLUMN IF EXISTS construction_structural_system; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_structural_system_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_structural_system_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_foundation; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_foundation_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_foundation_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_roof_shape; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_roof_shape_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_roof_shape_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_irregularities; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_irregularities_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_irregularities_source_links;