-- Falls eine Spalte bereits existiert, die jeweilige ALTER-Zeile überspringen.

ALTER TABLE articles ADD COLUMN manufacturer VARCHAR(255) NULL AFTER article_number;
ALTER TABLE articles ADD COLUMN manufacturer_part_number VARCHAR(255) NULL AFTER manufacturer;
ALTER TABLE articles ADD COLUMN datasheet_url VARCHAR(500) NULL AFTER description;
ALTER TABLE articles ADD COLUMN image_path VARCHAR(500) NULL AFTER datasheet_url;
