如何在模块之间共享相同的变量? [英] How to share the same variable between modules?

问题描述

我正在将Node.JS与Express.js一起使用，我需要在模块之间共享一个变量，我必须这样做，因为该变量是mysql连接池，该池在Node的开头创建了3个Mysql连接.js，然后我希望其他模块将使用这些连接，而无需重新创建其他池.

I'm using Node.JS with Express.js and I need to share a variable between modules, I have to do that because this variable is a pool of mysql connections, This pool creates 3 Mysql connections at the start of Node.js and then I would like that the other modules will use those connections without recreate other pools.

这可能吗?

谢谢

推荐答案

有2个选项:

• 将该变量设为全局变量，例如:global.MySQL_pool = ....这样，您可以使用MySQL_pool作为变量来在任何地方访问它.

• 将它传递给每个需要它作为功能参数的模块，例如:

• make that variable a global one, for ex: global.MySQL_pool = .... This way you can access it everywhere by using MySQL_pool as the variable.

• pass it for each module where you need it as a function param, for ex:

var MySQL_pool = ... var my_db_module = require('./db')(MySQL_pool);

var MySQL_pool = ... var my_db_module = require('./db')(MySQL_pool);

其中db.js是:

module.exports = function (pool) {
  // access the MySQL pool using the pool param here
}

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