Is it possible to connect any database from flex directly?
You can use asSQL as mentioned by michael, or use the Adobe Air runtime.
However, this must be said about using this library: It is EXTREMELY insecure to have a straight database connection from the client unless it's from Adobe Air since the db is local.
You don't want to send your username/password over the internet to connect to a database unless you really don't care about the data or security of your data. I would recommend you use a middleware solution, like PHP or Java that interfaces your database for your client to get the data it needs.
Not unless you use Adobe AIR for desktop at which time you'd be using the SQLLite api's to create/connect to a sqlite database file.
http://livedocs.adobe.com/flex/3/html/help.html?content=SQL_01.html
Anything else is going to require a back end service to handle such transactions.
You may try asSQL.
http://ntt.cc/2008/02/01/actionscript-mysql-driver-assql-access-database-from-flex.html
http://code.google.com/p/assql/source/browse/trunk/assql/asSQL_PureAS3/src/com/maclema/mysql/Connection.as
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What are the different ways available to get access to the data from the Progress procedures in the form of JSON? Other than creating PASOE instances, ODBC or JDBC? If I want to build an API that can communicate with Progress 4GL DB, what are the options available other than what I have mentioned above? Just to give an example I have a front end application which is build on JavaScript/Angular/ASP.NET CORE and if I want to make calls to Progress DB, how do I achieve it? It would be helpful if I can know any latest technologies that can be integrated to communicate with Progress 4GL DB.
If you run old-school appserver or webspeed you can set up a webservice that way.
For .Net (or Java) you can check the Open Client: https://docs.progress.com/bundle/openedge-open-clients/page/Introduction-to-Open-Clients.html
You could also develop some kind of server operating on a socket but I think sticking to tested techniques such as those you mention NOT wanting to use is the winning bet. Whatever you save in money not licensing PAS (if money is the issue) will be losts in time developing that server.
I have developed a Client/Server application for IM with Qt. So far messages are sent and displayed at the client side, but when the program is closed the messages are no longer available since a proper storage is missing.
I would like to keep the messages on the client devices and avoid to store everything on the server. I don't want to use a DB either since it needs to be installed and I would like to keep everything quite easy.
Therefore I was thinking of simply storing everything in an encrypted file, but I couldn't think of a proper format to do that.
Has anyone experience with that or any suggestions how to save the messages from different clients?
You do have a concern with data integrity in face of unplanned termination of your software, due to bugs in your code, transient hardware errors, power outages, etc. That's the problem that everyone using "plain files" usually ignores, as it's a hard problem to solve and requires extensive testing and know-how.
That's why you should use an embedded database. It will solve that, and many other problems as well. SQLite is a de-facto standard for applications such as yours. You can add any encryption you wish, as SQLite provides hooks that let you implement writing and reading of the pages. You'd do the encryption there.
One little-appreciated aspect of SQLite specifically is the amount of testing it gets during development. The test harness, most of it non-public, is probably worth way more than the published SQLite code (>1M USD). SQLite is used in aerospace applications, e.g. IIRC in code classified as DAL-B under DO-178B.
I am in the beginning stages of writing an angularjs client that talks to a RESTful ASP.net Web Api server and am trying to integrate Breeze. I have full control over both client and server code, but the one non-negotiable is that I have to connect to a DBISAM database that I'm sharing with a legacy Windows desktop app; so I can not take advantage of the Entity Framework that most Breeze Server examples use. I've successfully retrieved data by setting up a controller similar to the one in the NoDB example and am now trying to figure out the best way to get real data from my database. Also, I am able to get data from the DB using the ODBC connection, but I'm just not sure where that will fit in with the Breeze way of doing things.
Given all of that, here are my specific questions:
are there any Breeze Server examples showing how to retrieve/save data using a database connected via ODBC that I have somehow overlooked?
will I need to create an adapter to make this work? And if so, is the mongodb adapter the closest thing to use as an example of what that code should look like?
Without Entity Framework, is it still better to return the metadata from the server, or should I create it on the client instead?
I understood the documentation to say that it is easier to have the server be Breeze "aware", but is that still true when needing to use ODBC? Perhaps I should just use Breeze on the client side instead, similar to the Edmunds example?
thanks for any help with figuring out the best way to proceed!
I am planning to create sqlite table on my android app. The data comes from the the server via webservice.
I would like to know what is the best way to do this.
Should I transfer the data from the webservice in a sqlite db file and merge it or should i get all the data as a soap request and parse it in to table or should I use rest call.
The general size of the data is 2MB with 100 columns.
Please advise the best case where I can quickly get this data, with less load on the device.
My Workflow is:
Download a set of 20000 Addresses and save them to device sqlite database. This operation is only once, when you run the app for the first time or when you want to refresh the whole app data.
Update this record when ever there is a change in the server.
Now I can get this data either in JSON, XML or as pure SqLite File from the server . I want to know what is the fastest way to store this data in to Android Database.
I tried all the above methods and I found getting the database file from server and copying that data to the database is faster than getting the data in XML or JSON and parsing it. Please advise if I am right or wrong.
If you are planning to use sync adapters then you will need to implement a content provider (or atleast a stub) and an authenticator. Here is a good example that you can follow.
Also, you have not explained more about what is the use-case of such a web-service to decide what web-service architecture to suggest. But REST is a good style to write your services and using JSON over XML is advisable due to data format efficiency (or better yet give protocol-buffer a shot)
And yes, sync adapters are better to use as they already provide a great set of features that you will want to implement otherwise when written as a background service (e.g., periodic sync, auto sync, exponential backoff etc.)
To have less load on the device you can implement a sync-adapter backed by a content provider. You serialize/deserialize data when you upload/download data from server. When you need to persist data from the server you can use the bulkInsert() method in content-provider and persist all your data in a transaction
I have been successfully using SQLite as a data store for my web applications, but now I am implementing a web site with mod_perl, and am running into database locking issues.
As expected, my entire web application is loaded by the Plack Apache handler (Plack::Handler::Apache2) when the web server is started. Well, the first db query creates a lock on the entire database, and any subsequent query that has to modify the db fails.
What is my way out? Can I use SQLite in a persistent web environment or not? Should I be looking for some other db store?
I am not a fan of MySQL, and don't want to use it. I could potentially use PostGres, but I'd rather use something lightweight, and preferably sql-based as using key/value databases such as Tokyo Cabinet would require learning a whole new way. I'd rather really use SQLite.
If you have an open handle to the database, it can cause this issue. I have had problems when iterating over a result set during a log process causes the lock to stick around.
Try and fetch all the rows for the query and call $sth->finish() to clear up the lock. You will use a little more memory, but you will avoid the locking.
Knowing you are going to do this, you can make use of $sth->fetchall_arrayref() or $sth->fetchall_hashref()
Use Tokyo Cabinet's table database.