Add mysql dependency in the package.json file in the root of your project. Example of a package.json file:
{
"name": "Dribbit",
"description": "My default description",
"private": true,
"dependencies": {
"mysql": "~2.0.0"
},
"repository": {
"type": "git",
"url": "git@bitbucket.org:UserName/repo.git"
}
}
After saving package.json, run
npm install