How does mysql query products not sold in a certain period of time?

At the front-end time, my roommate asked me a question about mysql query:

There are three tables:

1. zd_product table zp_id primary key (product id) inputtime (product release time)

2. zd_order order table zp_id foreign key (product id) zo_id primary key (Order id) zo_voer_time (order completion time)

3. zd_ord_pro product order table zo_id foreign key (Order id) zp_id (product id)

Q: Can I use these three tables to find products that have been sold since the product was released to "NONE" within a month?

Here I will not talk about how we have discussed it. Let's look at it directly:

1. First, search for the product id that was sold in January and the data: data (the table named zd_order)

2. Continue to query the zd_order table through the data found in step 1, but add a not in (data)

3. In the first two steps, you have found the product id that has not been sold. Then you can check the product id if you want.

Statement:
Copy codeThe Code is as follows:
Select * from zd_product a1 left join zd_ord_pro a3 on a1.zp _ id = a3.zp _ id where a1.zp _ id in (select zp_id from zd_order where a1.zp _ id not in (select zp_id from zd_order a2 where a2.zo _ voer_time> a1.inputtime and a2.zo _ voer_time <a1.inputtime + 30 ))

This statement is not verified. If any error occurs, modify it.

Tip: The time addition must be converted to the timestamp.