google app engine - Datastore - select nearby posts using given co-ordinates -


I use App Engine Datastore with JDO to store data about all users' posts with Latitude ; The longitude of the place from which they have been posted.

With the current user's co-ordination, I want to get the adjacent post within the current X's X-km user.

At first I tried to ask a question for a range of latitude; Longitude, but this is not possible because the datastore does not support inequality filters on many properties.

According to RDBMS, it can be achieved only by calculating within the query.

How can I do this query in JDO? Is the place a better way to store data, where can calculate distance and get it easily? 1 - High performance on large datasets is a good solution for geospatial detection.

Below, you have to duplicate your search index data in GAE-Search.

The best way to use this is to use the datastore key with the datastore in the form of DAC-ID in the GAE-Search index where you have one-to-one mapping with the datastore unit (and Use the same key in the candy cache which is the facility of NNDB / Object etc.) Then come back from GAE-Search to bring the document-id from Memphor.

2 - The most convenient way. If you need a geographic search then it will work as it does not require combination with a condition and ranking or full text search. And if the data is not expected to grow so big that you see performance problems.


-

Comments

Post a Comment

Popular posts from this blog

Member with no value in F# -

After I am trying to convert F # to the following C # code: [StructLayout (LayoutKind.Sequential, charset = CharSet.Ansi)] Private class DOCINFOA {[MarshalAs (UnmanagedType.LPStr)] public string nomeDocumento; [Marshall (UnmanagedType.LPStr)] Public string arquivoSaida; [Marshall (UnmanagedType.LPStr)] Public String Tipodo; } I am doing the following: Named place printer module RawPrinterHelper = [& LT; StructLayout (LayoutKind.Sequential, charset = CharSet.Ansi) & gt;] Type DOCINFOA = [& LT; MarshalAs (UnmanagedType.LPStr) & gt;] Member this.nomeDocumento [& LT; MarshalAs (UnmanagedType.LPStr) & gt;] Member this.arquivoSaida [& LT; MarshalAs (UnmanagedType.LPStr) & gt;] Member This Tipoda [/ code> But I get: One type of definition is necessary for one or more members . Can I vacate these members? you val code> member : [& lt; StructLayout (LayoutKind.Sequential, charset = CharSet.Ansi) & gt;] Type DOCINFOA = [...
Read more

java - Joda Time Interval Not returning what I expect -

मेरे पास निम्न प्रोग्राम है import java.util। *; Import java.text। *; आयात करें org.joda.time। *; सार्वजनिक श्रेणी के स्कोप कंट्रोल {सार्वजनिक स्थिर अंतराल मिलनसार () {दिनांक समय currDate = नया दिनांक समय (2008, 4, 4, 15, 30, 0, 0); दिनांक समय epochDate = नया दिनांकटाइम (2000, 1, 1, 12, 0, 0, 0); अंतराल अंतराल = नया अंतराल (युरोप डेट, करोडेट); वापसी अंतराल; } सार्वजनिक स्थिर शून्य मुख्य (स्ट्रिंग [] आर्ग्स) {डबल दिनबात = मिलते समय ()। ToDurationMillis () / 1000/60/60/24; StdOut.println (daysBtween); }} मुझे आउटपुट मिल रहा है: 3016.0 लेकिन जो मैं देख रहा हूं वह है: 3016.1458333333 मैं क्या कर रहा हूँ ? toDurationMillis एक लंबा लौटा देता है, और प्रत्येक प्रभाग को int के रूप में घोषित किया जाता है। जावा इस प्रकार इनट्स को लॉन्ग में परिवर्तित कर देगा और डिवीजन को लंबे समय तक लौटाना होगा। परिणाम को अंत में दोहरे रूप में परिवर्तित करना। डबल्स का उपयोग करके अभिव्यक्ति करने के लिए जावा को बताने के लिए, अभिव्यक्ति के किसी भी घटक को दोहरे रूप में घोषित करें। उदाहरण के लिए: ...
Read more

c# - Showing a SelectedItem's Property -

So I have enabled a rightclick option for my DataGrid. I want to display the only chosen property but it is not behaving like what I would like it to display my name and additional. Public category Paymentinfo {public int PaymentNo {get; Set; } Public string date {get; Set; } Public Double Pay {get; Set; } Public Double Principle {get; Set; } Public Double Interest {get; Set; } Public Double Balance {Received; Set; }} Private Zero MenuItem_OnClick (Object Sender, RoutedEventArgs e) {MessageBox.Show (AmortGrid.SelectedItem.ToString ()); } I'm trying to apply it without using a View Module! If I place a breakpoint where the messagebox and the recipient place it on selected ITEM, then this property will display the payment. A date-payment-principle-interest-balance is the only value that needs payment. Was hoping that it would be something like this MessageBox.Show (AmortGrid.SelectedItem.PaymentNo.ToString ()); When you call ToString () So you get the class typ...
Read more