如何使用 Node-RED REST-API 按数字过滤

Question

我使用 Node-RED 为我的 MongoDB 创建了一个小型 REST-API。

这很好用：<node-red-url>:<node-red-port>/rest/demo 显示所有条目。

我什至可以过滤结果：附加 ?userName=demo 仅显示 {userName: "demo"} 的条目。

在我的数据库中，我有一些数值是数字。像{weight: 10} 这样的东西。请注意，这不是{weight: "10"}！

现在我只想要{weight: 10} 所在的条目。但是当我附加?weight=10 时，传输的参数将10 转换为"10"。这没有任何影响，因为我所有的 weight-values 都是数字而不是字符串。

我可以以某种方式将附录更改为按weight 过滤吗？还是我必须改进我的 REST 逻辑？

//编辑： 这是我的流程的样子：

[{"id":"c4a27b53.59303","type":"mongodb in","z":"99225255.0516b8","mongodb":"7e071505.7198bc","name":"","collection":"demo","operation":"find","x":660,"y":580,"wires":[["852d2853.264698"]]},{"id":"af5a916a.08366","type":"function","z":"99225255.0516b8","name":"parseQuery","func":"msg.payload = (msg.req.query);\n\nmsg.limit = 100;\nmsg.skip = 0;\n\nreturn msg;","outputs":1,"noerr":0,"x":330,"y":580,"wires":[["c4a27b53.59303"]]},{"id":"6b0b1b4b.eb8b2c","type":"http in","z":"99225255.0516b8","name":"","url":"/rest/demo","method":"get","swaggerDoc":"","x":120,"y":580,"wires":[["af5a916a.08366"]]},{"id":"852d2853.264698","type":"http response","z":"99225255.0516b8","name":"","x":950,"y":580,"wires":[]},{"id":"7e071505.7198bc","type":"mongodb","z":"","hostname":"192.168.100.166","port":"27017","db":"training","name":"debianTraining"}]

//编辑2： 更新

我用更多的服务器逻辑解决了这个问题：

if (msg.payload.hasOwnProperty('weight')) {
   msg.payload.weight = parseInt(msg.payload.weight);
}

我又添加了两个案例来搜索“大于”和“小于”：

if (msg.payload.hasOwnProperty('weightG')) {
   msg.payload = {"weight": {$gt: parseInt(msg.payload.weightG)}};
   delete msg.payload['weightG'];
}
if (msg.payload.hasOwnProperty('weightL')) {
   msg.payload = {"weight": {$lt: parseInt(msg.payload.weightL)}};
   delete msg.payload['weightL'];
}

到目前为止，这工作正常。

Answer 1

好的，已经查看了将 HTTP 查询转换为 Mongo 查询的函数节点，我认为在 Mongo 中不会有一个很好的方法可以动态地为任意对象执行此操作。

所有 HTTP 查询参数都将是字符串，因此如果您知道文档中的特定字段是数字，您可以只转换该字段。例如

msg.payload = (msg.req.query);

if (msg.payload.hasOwnProperty('weight')) {
   msg.payload.weight = parseInt(msg.payload.weight)
}

msg.limit = 100;
msg.skip = 0;

return msg;