INSERT INTO your_table (column1, column2, column3, category_id)
SELECT column1, column2, column3, new_category_id
FROM your_table
WHERE category_id = old_category_id;
INSERT INTO your_table (column1, column2, column3, category_id)
SELECT column1, column2, column3, new_category_id
FROM your_table
WHERE category_id = old_category_id;