Monster Market cleans up its data. A new table, cart_items, holds the products that customers put in their carts but did not buy.

Before each DELETE, run a SELECT with the same WHERE and look at the rows you will remove.

1. The shop stops selling posters. Remove the Posters category (id 5).
2. Remove every cancelled order. The first try fails. Read the error: it names the table that still points to the order. Remove those rows first.
3. Remove the cart rows that customers added before 1 June 2025.
4. Empty cart_items. The table must stay, because the shop uses it every day.