Is there a webapp that lets me draw out the structure of a database and link keys visually?
First of all, a pencil and paper or whiteboard is more useful until you get your schema right.
But I've found Gliffy to be a good online flowcharting solution. it supports db schema and some other useful types. You can save your work on the server and print out.
Related
I need to write an API which would provide access to data being served as HTML documents from a web server. I need for my users to be able to perform queries over the data.
Say on a web site there is a page which lists items and their owners. Then there is additional set of profile pages for owners which for each owner provide information about their reputation. An example query I may need to answer is "Give me ID's and owners of all items submitted in 2013 whose owners have reputation of at least 10".
Given a query to answer, I need to be able to screen scrape only the parts of the web site I need for answering the query at hand. And ideally cache the obtained information for future use with new queries.
I have no problem writing the screen scraping part, but I am struggling with designing the storage/query/cache part. Is there something about Clojure/Datomic that makes it an especially suitable technology choice for this kind of processing of data? I have been pointed in this direction before.
It seems a nice challenge but not sure about a few things: a) would you like to expose to your users a Datalog query box and so make them learn datalog-like syntax? b) what exact kind of results do you wish to cache, raw DB responses, html fomatted text, json ?
Anyway I suggest you to install and play a little bit with the Datomic console to get a grasp if you didn't before as it seems to me the more close idea to what you want to achieve atm https://www.youtube.com/watch?v=jyuBnl0XQ6s http://blog.datomic.com/2013/10/datomic-console.html
For the API I suggest you to use http://clojure-liberator.github.io/liberator/ as it provides sane defaults to implement REST services and let you focus on your app behaviour
We need a reasonable insert and query speed over huge tables so I considered using some noSQL adapter with Django. Unfortunately:
Django does not provide official support for noSQL databases.
In our original schema some Big Data are relational to other Big Data making the data duplication unacceptable.
Project deadlines are enemies of hot stuff like this.
So, as far I can see, PostgreSQL should be the way to go for this scenario, right?!
Please let me know any other detail that may be relevant to this question!
Bonus to anyone that can point out some useful database techniques like database sharding...
Well, there is a fork of django project that uses MongoDb as the backend.You can read about it here . The Code on GitHub is here.You give some heads up, MongoDB is a NOSQL db that does support sharding and replication. So i think this might something that you are looking for.
I have a long list of towns and cities, and I'd like to add latitude and longitude information to each of them.
Does anyone know the easiest way to generate this information once?
See also Geocode multiple addresses
The first part of the third video shows how to get latitude and Longitude using Google Refine and geocoding. No need to write a new script. Ideal for doing this kind of change once.
http://code.google.com/p/google-refine/
Or use www.geonames.org - there's language APIs for that. Or Open Street Map's Nominatim: http://wiki.openstreetmap.org/wiki/Nominatim - google have slightly more restrictive terms of service.
You can use the Google Geocoding API. Check the API at this URL: http://code.google.com/apis/maps/documentation/geocoding/
What follows next is writing some code. I am doing something similar in C# and it is quite easy here.
Most geocoding services can handle queries with only administrative names which is what you're after, e.g., municipality and region. So I'd choose one you like that also handles batch or bulk requests, e.g., the Bing Spatial Data API (here's an article on batch geocoding with it.)
An alternative approach that might be useful if you're on a budget and have a lot of these to do would be to download the Geonames database and write a bit of code to import it into your database or index it; then query it however and how often you like, e.g., if you put your places in another table you could SELECT [...] FROM my_places LEFT JOIN geonames [...]. I used to import Geonames DB into a vanilla PostgreSQL nightly and probably still have the code in a git repo somewhere if that's a route you want to try (comment and I'll find it and attach.)
For a service that uses google, which I find most accurate.
Look at http://www.torchproducts.com/tools/geocode
Web services and web APIs have managed to increase the accessibility of the information stored and catalogued on the internet. They have also opened up a vast array of enterprise power functionality for smaller thin client applications.
By taping into these services developers can provide functionality that would have taken them months perhaps years to set up. They can combine them into single applications that make life generally easier for its users.
Whether displaying information about the music being played, finding items of interest in the locale of the user or just simply tweeting and blogging from the same application - the possibilities are growing everyday.
I want to know about the most interesting or useful services that are out there, especially ones that most of us may not have heard about yet. Do you maintain an API or service? or do you have a clever mash up that provides even more benefits than the originals?
YQL - Yahoo provide a tool that lets you query many different API's across the web, even for sites that don't provide an API as such.
From the site:
The Yahoo! Query Language is an
expressive SQL-like language that lets
you query, filter, and join data
across Web services.
...
With YQL, developers can access and
shape data across the Internet through
one simple language, eliminating the
need to learn how to call different
APIs.
The World Bank API is pretty cool. Google uses it in search results. My favourite implementations are the cartograms at worldmapper.
(source: worldmapper.org)
It's very niche, but I happen to think the OpenCongress API is amazing.
Less niche: Google Translate has an API which will guess the language of something. You'd be AMAZED how frequently this comes in handy (even though it's not as tweakable as you'd like and is not trained on small samples).
I was just about to have a stab at using the SoundCloud API
I know many people who already use for sharing their musical masterpieces and its a pretty good site. Hopefully the api will be as well!
I like the RESTful API for weather.com. It's free and very useful for the new age of location-aware apps: https://registration.weather.com/ursa/xmloap/step1
It does require registration, but they don't spam you or anything - it's just to provide you a key to use the API.
Ah yes - here's another one I've been meaning to check out but haven't tried yet
The BBC offer a bunch of apis/feeds that look very promising
http://ideas.welcomebackstage.com/data
They include apis for accessing schedule data for both TV and Radio listings along with all kinds of news searches. It even looks like they'll be offering some sort of geo-location service soon so it will be interesting to see what that has to offer
Another interesting one for liberal brits! ;)
The Guardian news paper have their own api
http://www.guardian.co.uk/open-platform
MuiscBrainz
Excellent service for music mashups.
Not so many knows that Last.FM initial database was scraped from this service.
The United States Postal Service offers a web service that does address standardization. Quite useful in reducing clutter and cleaning data before it gets put into your database.
I'm aware of the WoW add-on programming community, but what I can find no documentation on is any API for accessing WoW's databases from the web. I see third-party sites like WoWHeroes.com and Wowhead use game data (item and character databases,) so I know it's possible. But, I can't figure out where to begin. Is there a web service I can use or are they doing some sort of under-the-hood work that requires running the WoW client in their server environment?
Sites like Wowhead and WoWHearoes use client run addons from players which collect data. The data is then posted to their website. There is no way to access WoW's database. Your best bet is to hit the armory and extract the XML returned from your searches. The armory is just an xml transform on xml data returned.
Blizzard has recently (8/15/2011) published draft documentation for their RESTful APIs at the following location:
http://blizzard.github.com/api-wow-docs/
The APIs cover information about characters, items, auctions, guilds, PVP, etc.
Requests to the API are currently throttled to 3,000 per day for anonymous usage, but there is a process for registering applications that have a legitimate need for more access.
Update (January 2019): The new Blizzard Battle.net Developer Portal is here:
https://develop.battle.net/
Request throttling limits and authentication rules have changed.
Characters can be mined from the armory, the pages are xml.
Items are mined from the local installation game files, that's how wowhead does it at least.
It's actually really easy to get item data from the wow armory!
For example:
http://www.wowarmory.com/item-info.xml?i=33135
View the source of the page (not via Google Chrome, which displays transformed XML via XSLT) and you'll see the XML data!
You can use search listing pages to retrieve all blue gems, for example, then use an XML parser to retrieve the data
They are parsing the Armory information from www.wowarmory.com. There is no official Blizzard API for accessing it, but there is an open source PHP solution available (http://phparmory.sourceforge.net/)
Maybe a little late to the party, but for future reference check out the WoW API Documentation at http://blizzard.github.com/api-wow-docs/
Scraping HTML and XML is now pretty much obsolete and also discouraged by Blizzard.
The documentation:
http://blizzard.github.com/api-wow-docs/
enjoy
Sites like those actually get the data from the Armory. If you pull up any item, guild, character, etc. and do 'View Source' on the page you will see the XML data coming back. Here is a quick C# example of how to get the data.
This third-party site collection data from players. I think this collection based on addons for WoW or each player submit information manualy.
Next option is wraping wow site and parsing information from websites (HTML).
this is probably the wrong site for your question, but you're thinking of the wowarmory xml stuff. there is no official wow api. people just do httprequests and get the xml to do number crunching stuffs. try googling around. there are some libs out there in different languages that are already written for you. i know there are implementations in php/ruby. i was working on one in .net a while back until i got distracted. here's an article which kinda sums this all up.
http://www.wow.com/2008/02/11/mashing-up-wow-data-when-we-can-get-it-in-outside-applications/
Wowhead and other sites generally rely on data gathered by users with a wow add-in.
Wowhead also has a way for other sites to reference that data in hover pop-ups, so their content gets reused on a number of sites.
Powered by Wowhead
For actual ingame data collection:
cosmos.exe is what thottbot for example uses. It probably uses some form windows hack (dllinjection or something) or sniffs packets to determine what items have dropped and etc. (intercepts traffic from the wow server to your client and decodes it). It saves this data on the users computer and then uploads it to a webserver for storage. I don't know if any development libraries were created for this sort of thing.