为什么 express (node.js) 需要参数来删除请求？

Question

I made todo react app where user clicks on delete button it fetches delete request to my node.js server.

const deleteTodo = (id) => {
  const q = `DELETE FROM todos WHERE id=${id}`;
  connection.query(q, (err, results) => {
    if (err) throw err;
    console.log('delete', results)
  })
}

However, when I simply went with router option below,

app.delete('/', function (req, res) {
  (some function) 
})

app wouldn't delete just like this.

On the other hand, by simply making it

app.delete('/todos/:id', function (req, res) {
  (some function) 
})

it will start functioning again.

Why is this so?

Answer 1

I think your question has some missing information.
In particular, how you're calling deleteTodo and what the error actually is.

If I were to make a guess, when /todos/:id is specified, it becomes possible to use req.params.id .
However, when it's / , req.params.id is undefined. When req.params.id is undefined, the query becomes invalid.

Refer to express documentation for more details.