문제가 해결된거 같아여

node js 다시 설치하고

mysql2도 전역으로 다시 설치하니까 된거 같아여

C:\node_bird_11\back>npm i -g mysql2
+ mysql2@1.7.0
added 15 packages from 19 contributors in 1.189s

C:\node_bird_11\back>
C:\node_bird_11\back>
C:\node_bird_11\back>sequelize db:create

Sequelize CLI [Node: 10.16.3, CLI: 5.5.1, ORM: 5.19.0]

Loaded configuration file "config\config.json".
Using environment "development".

ERROR: Access denied for user 'root'@'localhost' (using password: YES)


C:\node_bird_11\back>sequelize db:create

Sequelize CLI [Node: 10.16.3, CLI: 5.5.1, ORM: 5.19.0]

Loaded configuration file "config\config.json".
Using environment "development".
Database react-nodebird created.