good morning I'm considering creating a Universal app windows 10 limited to the classic desktop and mobile app CRUD but I wanted to make sure that both devices were using the same database, I wanted to ask if you can change the connection string and indicate a specific directory in the local network. I wanted to avoid making a WebAPI REST.
This is the path to change:
path = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "db.sqlite");
If your data is small in size ( < 100kb ), how about you utilize the Roaming Folder ?
Related
I have recently created a very small Google Compute Engine instance, naively thinking it's one of those easily scalable things Google people keep raving about.
I used the quick deployment feature of Wordpress and it all installed itself nicely, so I started configuring and adding data etc.
However, I then found out that I can't scale an existing instance (i.e. it won't allow me to change the instance type to a bigger one. I don't get why not, but there you go.), so it looks like I need to find a way to migrate my Wordpress installation to a new instance.
Will I simply be able to create a new instance and point it at the persistent disk my small instance currently uses, et voila, Bob's your uncle?
Or do I need to manually get the files and MySql data off the first instance and re-import into an empty new instance?
What's the easiest way?
Any advise or helpful links would be appreciated.
Thanks.
P.S.: Btw, should I try to use the Google Cloud SQL store instead of a local MySql installation?
In order to upgrade your VM:
access the VM's settings in the Developers Console (your project -> Compute -> Compute Engine -> VM instances -> click on the VM's name)
Scroll down to the "Disks" section, and un-check "Delete boot disk when instance is deleted"
Delete the VM in question. Take note that the disk, named after the instance, will remain.
Create a new VM, selecting "Existing disk" under Boot disk - Boot source. In the next box down, select the disk from point 3 above, as well as a bigger machine type.
The resulting new instance will use the existing disk from the old one, with improved hardware / performance.
As for using Cloud SQL in lieu of a VM-installed database, it's perfectly feasible, and allows to adjust the Cloud SQL instance to match your actual use. A few consideration when setting up this kind of instance:
limit the IPs allowed to connect to your Cloud SQL instance to your frontend's IP, and perhaps the workstation's IP or subnet from which you maintain the database out of.
configure Cloud SQL to use SSL certificates.
Sammy's answer covers the important stuff I just wanted to clarify how your files are arranged on the two disks that are attached to your instance:
The data disk contains /var/www/ which is all of the wordpress files. It's mounted on the instance at /wordpress
The boot disk contains everything else, including the MySQL database that was created for the Wordpress installation.
I'm currently working with SterlingDB (not the phone 7 version) and would like to be able to access the same Sterling Database from 2 different applications (and therefore different AppDomains).
I have ascertained that even when you pass a FileSystemDriver to the RegisterDatabase method:
engine.SterlingDatabase.RegisterDatabase<PodcastDatabase>(new FileSystemDriver("MyTestApp/"));
you end up with 2 different databases:
I:\Users\Dave\AppData\Local\Sterling Database\TestMeGo\1123790033 and
I:\Users\Dave\AppData\Local\Sterling Database\TestMeGo\1728918701
This is presumably because the apps are contained in separate AppDomains and the IsolatedStorage which is used by Sterling is compartmentalised accordingly.
Is there a way to have just one Sterling database which more than 1 app can access?
Thanks
It should be possible, as you can read here. You either let the storage be based on the XAP url, or on the source domain. If you can get both apps to be from the same source domain, and use the GetUserStoreForSite method, you should be able to get it to work.
I have a simple access database that resides on a network drive. All of the people that need to make any modifications to this database have access on their machine, but they would like to have a read-only website just displaying the data contained in it. I set up a website and tried using the accessdatasource, and while I could connect, it had issues whenever a user had the database open in access. I swapped to using a sqldatasource with a connection string set up according to www.connectionstrings.com, but I seem to be having either the same or similar issues, depending on how I set up the string/database. Basically, the entire issue is, if the database is opened by any user, the webpage is prevented from opening the database. Is it possible to open the database read only from the webpage?
It is an access 2000 database, but everyone is using copies of access 2007, and in all of these instances, the ASP.NET user has read/write access to the network directory containing the database, and read access to the database itself.
When I use the connection string:
ConnectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\\<source>\<database>.mdb;User Id=<USER>;Password=<PASSWORD>;Mode=Share Deny Write;"
Where is not the default "admin" user, and is configured to have open/run (not open/exclusive) permissions on the database, I get the error:
Cannot start your application. The workgroup information file is missing or opened exclusively by another user.
As far as I can tell, there is no workgroup information file, but I am not really sure what I am doing there.
When is the default "admin" user, I get the error:
Could not use ''; file already in use.
If someone has the database currently open, otherwise, it works fine.
And finally, if I use the connection string:
ConnectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\\<source>\<database>.mdb;User Id=<USER>;Password=<PASSWORD>;Mode=Read;"
I get the error:
Could not lock file.
I have been googling this for the past several days now and I feel like I've just been going around in circles. Any insight at all would be appreciated.
As it's Access 2000 format there will definately have to be a workgroup file (.mdw) even if that has no security set as such. I would try the connection string whereby you also specify the workgroup location e.g:
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\mydatabase.mdb;Jet OLEDB:System Database=system.mdw;User ID=myUsername;Password=myPassword;
Furthermore, I wouldn't recommend setting the read/write properties in the connection string, instead I think you would be better to create an account in the workgroup file and only assign it read only priviledges.
Update:
This is the ODBC connection method:
Driver={Microsoft Access Driver (*.mdb)};Dbq=C:\mydatabase.mdb;Uid=Admin;Pwd=;
I'm working on an Adobe AIR application which can upload files to a web server, which is running Apache and PHP. Several files can be uploaded at the same time and the application also calls the web server for various API requests.
The problem I'm having is that if I start two file uploads, while they are in progress any other HTTP requests will time out, which is causing a problem for the application and from a user point of view.
Are Adobe AIR applications limited to 2 HTTP connections, or is something else probably the issue?
From searching about this issue I've not found much but one article did indicated that it wasn't limited to just two connections.
The file uploads are performed by calling the File classes upload method, and the API calls are done using the HTTPService class. The development web server I am using is a WAMP server, however when the application is released it will be talking to a LAMP server.
Thanks,
Grant
Here is the code I'm using to upload the file:
protected function btnAddFile_clickHandler(event:MouseEvent):void
{
// Create a new File object and display the browse file dialog
var uploadFile:File = new File();
uploadFile.browseForOpen("Select File to Upload");
uploadFile.addEventListener(Event.SELECT, uploadFile_SelectedHandler);
}
private function uploadFile_SelectedHandler(event:Event):void
{
// Get the File object which was used to select the file
var uploadFile:File = event.target as File;
uploadFile.addEventListener(ProgressEvent.PROGRESS, file_progressHandler);
uploadFile.addEventListener(IOErrorEvent.IO_ERROR, file_ioErrorHandler);
uploadFile.addEventListener(Event.COMPLETE, file_completeHandler);
// Create the request URL based on the download URL
var requestURL:URLRequest = new URLRequest(AppEnvironment.instance.serverHostname + "upload.php");
requestURL.method = URLRequestMethod.POST;
// Set the post parameters
var params:URLVariables = new URLVariables();
params.name = "filename.ext";
requestURL.data = params;
// Start uploading the file to the server
uploadFile.upload(requestURL, "file");
}
Here is the code for the API calls:
private function sendHTTPPost(apiFile:String, postParams:Object, resultCallback:Function, initialCallerResultCallback:Function):void
{
var httpService:mx.rpc.http.HTTPService = new mx.rpc.http.HTTPService();
httpService.url = AppEnvironment.instance.serverHostname + apiFile;
httpService.method = "POST";
httpService.requestTimeout = 10;
httpService.resultFormat = HTTPService.RESULT_FORMAT_TEXT;
httpService.addEventListener("result", resultCallback);
httpService.addEventListener("fault", httpFault);
var token:AsyncToken = httpService.send(postParams);
// Add the initial caller's result callback function to the token
token.initialCallerResultCallback = initialCallerResultCallback;
}
If you are on a windows system, Adobe AIR is using Microsofts WinINet library to access the web. This library by default limits the number of concurrent connections to a single server to 2:
WinInet limits the number of simultaneous connections that it makes to a single HTTP server. If you exceed this limit, the requests block until one of the current connections has completed. This is by design and is in agreement with the HTTP specification and industry standards.
... Connections to a single HTTP 1.1 server are limited to two simultaneous connections
There is an API to change the value of this limit but I don't know if it is accessible from AIR.
Since this limit also affects page loading speed for web sites, some sites are using multiple DNS names for artifacts such as images, javascripts and stylesheets to allow a browser to open more parallel connections.
So if you are controlling the server part, a workaround could be to create DNS aliases like www.example.com for uploads and api.example.com for API requests.
So as I was looking into this, I came across this info about using File.upload() in the documentation:
Starts the upload of the file to a remote server. Although Flash Player has no restriction on the size of files you can upload or download, the player officially supports uploads or downloads of up to 100 MB. You must call the FileReference.browse() or FileReferenceList.browse() method before you call this method.
Listeners receive events to indicate the progress, success, or failure of the upload. Although you can use the FileReferenceList object to let users select multiple files for upload, you must upload the files one by one; to do so, iterate through the FileReferenceList.fileList array of FileReference objects.
The FileReference.upload() and FileReference.download() functions are
nonblocking. These functions return after they are called, before the
file transmission is complete. In addition, if the FileReference
object goes out of scope, any upload or download that is not yet
completed on that object is canceled upon leaving the scope. Be sure
that your FileReference object remains in scope for as long as the
upload or download is expected to continue.
I wonder if something there could be giving you issues with uploading multiple files. I see that you are using browserForOpen() instead of browse(). It seems like the probably do the same thing... but maybe not.
I also saw this in the File class documentation
Note that because of new functionality added to the Flash Player, when publishing to Flash Player 10, you can have only one of the following operations active at one time: FileReference.browse(), FileReference.upload(), FileReference.download(), FileReference.load(), FileReference.save(). Otherwise, Flash Player throws a runtime error (code 2174). Use FileReference.cancel() to stop an operation in progress. This restriction applies only to Flash Player 10. Previous versions of Flash Player are unaffected by this restriction on simultaneous multiple operations.
When you say that you let users upload multiple files, do you mean subsequent calls to browse() and upload() or do you mean one call that includes multiple files? It seems that if you are trying to do multiple separate calls that that may be an issue.
Anyway, I don't know if this is much help. It definitely seems that what you are trying to do should be possible. I can only guess that what is going wrong is perhaps a problem with implementation. Good luck :)
Reference: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/FileReference.html#upload()
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/FileReference.html#browse()
Just because I was thinking about a very similar question because of an error in one of my actual apps, I decided to write down the answer I found.
I instantiated 11
HttpConnections
and was wondering why my Flex 4 Application stopped working and threw an HTTP-Error although it was working pretty good formerly with just 5 simultanious HttpConnections to the same server.
I tested this myself because I did not find anything regarding this in the Flex docs or on the internet.
I found that using more than 5 HTTPConnections was the reason for the Flex application to throw the runtime error.
I decided to instantiate the connections one after another as a temporally workaround: Load the next one after the other has received the data and so on.
Thats of course just temporally since one of the next steps will be to alter the responding server code in that way that it answers a request that contains the results of requests to more then one table in one respond. Of course the client application logic needs to be altered, too.
What's the standard way of storing user preferences in a Flex application for AIR? I need to store simple parameters like lists of recently opened files, window positions and sizes etc.
my favorite way to do it is to combine a VO with LSO (local shared object). If you have a LOT of settings, this doesn't work too well. The advantage is that you get a strongly typed settings object which is therfore bindable and has code introspection and completion.
The cool thing is it's only about 5 lines of code to manage an LSO. In addition, it's also pretty easy to manage a local encrypted store if you want to store any sensitive data.
registerClassAlias("SettingsVO",SettingsVO); //This lets us store a typed object in LSO
var settings:SettingsVO;
var settingsSO = SharedObject.getLocal("settings");
//Check to make sure settings exist... if not, create a new settings object
if( settingsSO.size && settingsSO.data && settingsSO.data.settings){
settings = settingsSO.data.settings as SettingsVO;
}else{
settings = new SettingsVO();
}
Now if you want to save settings you simply do
settings.someSetting = "newValue";
settingsSO.data.settings = settings;
settingsSO.flush();
And this solution works on BOTH AIR and Flex in any browser. Newer browsers will delete this data when clearing cookies, so beware of that.
I think the most flexible way is to use a local SQLite database. It gives you unlimited, structured storage and encryption if needed. See Peter Elst's introduction if you want to get more info.
There is no "Standard" way, but there are a lot of approaches, all which boil down to storing the user's preferences, then loading them up at runtime based on some uesr credentials, then changing the app based on those preferences.
You may store them in a server side database, such as SQL Server or MySQL; then have flex call a service which queries the database and returns the data.
You may store them as Shared Objects, which are the Flash version of browser cookies. (I believe they work on AIR applications too). This can get cumbersome with lots of data.
You may store them in an XML document and throw them on the server. Conceptually this is not much different than storing them in a server side database; but could get very tedious if you have a lot of users.
You could also store them, in an AIR app, locally using a SQLite database. SQLite is an embedded database used in Adobe AIR.
I don't bother with any of the fancy stuff. Just store it in an xml file in the application directory. Done.
Filestream does throw an error if you try to store it using File.applicationDirectory. I just trick the program...
var trickFile:File = File.applicationDirectory;
var file:File = new File(trickFile.nativePath + mySettings.xml);
Air falls for it every time.