Realization of sql language query statement in warehouse management

It should read:

Case aa. The number at aa. Quantity > 0 and then aa. End of other quantity 0

In addition:

Inventory generation, if you think this is not enough, tell you a train of thought:

The basic form should include: receipt document and delivery document;

Account books should include: quantity account, detailed account and amount account;

Then use the stored procedure: realize account entry;

Finally: query in the account book table after posting!

Yun Chi software!