在package.json中包含依赖项时遇到麻烦

Question

I have an angular project (really just the docs tutorial ) and I want to include the node-mysql module in my project- doesn't have to be installed globally.

Not sure I understand how this works but I thought all I have to do was add this module to package.json as a dependency and run npm install, but I get an error:

    PS> cat .\package.json
    {
      "version": "0.0.0",
      "private": true,
      "name": "angular-phonecat",
       ...
      "dependencies": {
        "node-mysql": ">=2.5.0"
      },
      "devDependencies": {
        "karma": "^0.12.16",
       ...

The error:

PS> npm install
npm WARN package.json karma-chrome-launcher@0.1.7 No README data
npm ERR! notarget No compatible version found: node-mysql@'>=2.5.0'
npm ERR! notarget Valid install targets:
npm ERR! notarget ["0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1"]
npm ERR! notarget
npm ERR! notarget This is most likely not a problem with npm itself.
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.

npm ERR! System Windows_NT 6.1.7601
npm ERR! command "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install"
npm ERR! cwd C:\testangular\ticketsys\angular-phonecat
npm ERR! node -v v0.10.32
npm ERR! npm -v 1.4.28
npm ERR! code ETARGET
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     C:\testangular\ticketsys\angular-phonecat\npm-debug.log
npm ERR! not ok code 0

How can I include this dependency in my project?

Answer 1

Node-mysql version >2.5 is not out yet. Node-mysql is on version 0.4.1. I suspect you are looking for just the regular mysql npm module. Mysql on npm is on version 2.5.4.

Try using this instead:

"mysql": ">=2.5.0"

If you go to this page: https://github.com/felixge/node-mysql . They say in the install instructions to use npm install mysql. This might be a bit confusing since their github page is node-mysql.

Alternatively instead of adding this manually to the dependency you could go ahead and do the following:

npm install mysql --save 

This will only install the most up to date one locally (Not globally, if you wanted to install it globally you could add the -g flag, but since you don't need that dont!).

Answer 2

As mentioned in other answers, npm is not recognizing the version you have specified. I would recommend removing that line from your package.json and instead running a single command:

npm install --save mysql

This will install the dependency locally AND add the line to your package.json(that's what the --save flag does). This automatically defaults to the most recent stable version of node-mysql.

In general, the only time you'll want to specify an actual version in your package.json is if a library patched over some features you actually wanted, in which case you could specify a version so that the necessary features are always there. So definitely start using the --save flag when you can. It's super useful. Best of luck!