mysql problem collection

environment

mysql 8
mac

question

Enter the mysql command show databases; appears

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘databases’ at line 1

Solution : Before entering the database, mysql8 can only recognize commands in uppercase letters. Use SHOW databases;
createpool detailed explanation:
https://blog.pkcms.cn/archives/1511

TypeError: app.use() requires a middleware function

Problem: Run the node app.js file, and an error occurs when starting the server.
Solution: Check whether the router variable is exported in the routing file.

Reference link: TypeError: app.use() requires a middleware function

Order

Delete database: drop database <database name>;