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; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_roof_covering_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_roof_covering_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_decorative_features; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_decorative_feature_materials; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_decorative_feature_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_decorative_feature_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_internal_wall; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_internal_wall_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_internal_wall_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_external_wall; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_external_wall_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_external_wall_source_links; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_ground_floor; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_ground_floor_source_type; ALTER TABLE buildings DROP COLUMN IF EXISTS construction_ground_floor_source_links;