Json-server 错误：数据必须是对象。 需要将 JSON 数组更改为 JSON 对象

Question

I can't start my json-server, because this REST API : gives me a JSON Array, but I need a JSON Object to run json-server. Is it possible to run json-server with an JSON Array, or can I construct my own db.json?

I've tried to put the JSON Array into a db.json file and removing the squared brackets, but because it was an array previous, the commas give me an error. So manually changing db.json is also not possible.

npm json-server --port 3001 --watch db.json

fires this error message:

Error: Data must be an object. Found object.See https://github.com/typicode/json-server for example.

UPDATE: I've simply wrapped the array with curly braces and added a property to it like this:

{ "countries": [{"name": ...

...

}]}

Now I've got a JSON Object in db.json and I can run json-server.

Answer 1

In case others get here. Assuming you have an array of countries with their names, you want it in the form

{ 
    "countries": [ {"id": 1, "name": "Narnia"}, {"id":2, "Sacoridia"}, ...]
}

The server can simulate multiple "tables" so you could add another line like

    "cities": [ {"id":1, "country_id": 1, "name":"Cair Paravel", "capital":1},...]

Answer 2

Since the data is in the form [{"name":"country name", ...}, {"name":"country name 2", ...}, ... ] , you'd have to transform it by extracting for example the name, or whatever attribute you want, as key, to get the format { "country name": { ... }, "country name 2": { ... },... } .

For example, this could be done with Javascript as:

function transform(data) {
  var transformedObject = {};
  for(var i = 0; i < data.length; i++) {
    transformedObject[data[i].name] = data[i];
  }
  return transformedObject;
}