在另一个RethinkDB查询中使用结果?

I want to send a http post with an address, which will grab a doc from the database. I would like to then use that doc's geodata in a getNearest function, ultimately returning the nearest four other locations. How do I go about stringing these two queries together?

我想发送一个带有地址的http post，它将从数据库中获取一个doc。然后我想在getNearest函数中使用doc的地理数据，最终返回最近的四个位置。如何将这两个查询串在一起?

r.table('dealer_locations').filter(function(dealer) {
return {
      dealer :  ("Address").match(request.body.Address)
      .getNearest(dealer, {
            index: 'geodata',
            maxResults: 4
          })
      }
    }).run(conn, function(error, cursor) {
      if (error) {
        handleError(response, error);
      } else {
        cursor.toArray(function(error, results) {
          if (error) {
            handleError(response, error);
          } else {
            response.send(results);
          }
        });
      }
    });

1 个解决方案

#1

I'll reformulate the question just to make a bit more clear:

我将重新表述这个问题，让大家更清楚一点:

Problem

问题

Given a specific document with geodata, I want to also return the four nearest locations to that location.

给定一个带有地理数据的特定文档，我还想返回到该位置的四个最近位置。

Solution

解决方案

First, make sure that you've creating the geo index in the table you want to query:

首先，确保在要查询的表中创建了geo索引:

r.table('dealer_locations').indexCreate('location', { geo: true })

After that, make sure that you've inserted a r.point object into the document. You can't just use geo indexes on just any property. They have to be r.points.

然后，确保插入了一个r。将对象指向文档。不能只在任何属性上使用geo索引。它们必须是r点。

r.table('dealer_locations')
  .insert({
    name: 'San Francisco', 
    location: r.point(37.774929, -122.419416)
  })

After you've inserted all your documents and they all have r.points property on the same property you created an index for, now you can start querying them.

插入所有文档后，它们都有r。在创建索引的相同属性上的points属性，现在可以开始查询它们。

If you want to get all the nearest locations for a location, you can do as follows:

如果您想获取一个位置的所有最近的位置，您可以做以下工作:

r.table('dealer_locations')
 .filter({ name: 'San Francisco' })(0)
 .do(function (row) {
   return r.table('dealer_locations')
     .getNearest(row('location'), { index: 'location', maxResults: 4 })
 })

If you want to append the closets locations to a document, so that you can return both the document and the nearest locations at the same time, you can do that using the merge method.

如果希望将closet位置附加到文档中，以便可以同时返回文档和最近的位置，那么可以使用merge方法。

r.table('dealer_locations')
 .filter({ name: 'San Francisco' })(0)
 .merge(function (row) {
   return {
     nearest_locations: r.table('dealer_locations')
       .getNearest(row('location'), { index: 'location', maxResults: 4 })
   }
 })

Finally, if you want to get all the nearest locations, based on an address (supposing your document has both an address property with a string and a location property with an r.point), you can do something like this:

最后，如果您想根据一个地址获得所有最近的位置(假设您的文档有一个带字符串的地址属性和一个带r点的位置属性)，您可以这样做:

r.table('dealer_locations')
 .filter(r.row('address').match(request.body.Address))
 (0) // Only get the first document
 .do(function (row) {
   // Return the 4 documents closest to the 'location' if the previous document
   return r.table('dealer_locations')
     .getNearest(row('location'), { index: 'location', maxResults: 4 })
 })

That being said, the problem with this might be that you might match multiple addresses which are not necessarily the ones you want to match!

话虽如此，问题可能在于您可能匹配多个地址，而这些地址不一定是您想匹配的地址!

#1