1.mybatis use update operations get returned id, the update statement added selectKey inside.
<selectKey resultType="java.lang.Integer" keyProperty="id" order="BEFORE" >//AFTER
SELECT LAST_INSERT_ID()
</selectKey>
2. Call the remote interface
Body for use as a raw POST request when the request can only be acquired by the parameter self.request.body.
3. When writing code, to minimize interaction with the database, to reduce response times.
4. The concept of the program time for space, computation time is the CPU time, memory space is a space.
Self-understanding, by increasing the CPU's operation, take up less memory space. Or come back.