Database Users

DataManagement Library for Easy Android Database Storage

Storing objects to a Database for an Android application should be fast and easy as:
Code:
dm.add(new StorableClass());
DataManagement is a new open source library that allows you to do just that.
DataManagement is a Java Android library designed to help easily and efficiently store aggregate classes to an SQLite database. It eliminates the need to write separate classes to manage database – object interactions and allows developers to use simple methods to store, query, update, and delete objects. The library is capable of storing all objects of classes whose instance variables are either primitive data types or are themselves objects of another storable class. The DataManagement Library condenses many standard database features into several simple methods. It is fully open source and the code can be found at http://epsilonlabsllc.github.com/DataManagement
Examples:
Creating a Storable Class:
Code:
public class StorableClass{
@Id
private int ident;
private int num1;
private double num2;
private String num3;
private boolean num4;
public static final int num5 = 3;
private OtherStorableClass[] ds2;
}
A storable class must meet two requirements. First, the class must have a private instance variable of type int that will be used as the id number of the object. This variable may be read by the application, but the application should not have the capability to write to or change this variable in anyway. This variable is identified by the system with an @Id annotation. In addition, the class should not have any instance variables that are not either primitive types, strings, or other storable objects.
Instantiating a DataManager Object:
Code:
DataManager dm = new DataManager(context);
The open method accepts the calling Context that is going to use the database. Usually this should be the calling Activity.
Opening a Database for Use:
Code:
dm.open();
This method must be called before the database is used in any way.
Closing a Database After Use:
Code:
dm.close();
This method should be called after all database operations have been performed.
Adding an Object to the Database:
Code:
int id = dm.add(new StorableClass());
The add method accepts an object of a storable class as its only parameter and adds it to the database. It returns its id in the database for future use.
Retrieving a Specific Item from the Database by ID:
Code:
StorableClass storableObject = dm.get(StorableClass.class, id);
The get method accepts two parameters: the data type of the stored object and the Id number of the object (the return value of the add method).
Retrieving All Objects of a Given Type Stored in the Database as a Collection:
Code:
storableObjectCollection = dm.getAll(StorableClass.class);
The getAll method’s only parameter is the class of the objects that should be retrieved.
Retrieving a Collection of Storable Objects that match a given criteria:
Code:
Collection<StorableClass> storableObjectCollection = dm.find(StorableClass.class, 5, "num1");
The find method accepts three parameters: the data type of the stored object, the value that is being searched for, and the name of the instance variable as a string. This method is overloaded in such a way that the second parameter may be any primitive value or a string.
Updating an Object in the Database:
Code:
dm.update(id, updatedObject);
The update method accepts two parameters: The id number of the object being updated and the updated object that will replace the existing one I the database. If the id number of the new object and the id number given as the first parameter do not match, the object’s id will be overwritten.
Deleting an Object by its Id number:
Code:
dm.delete(StorableClass.class, id);
The delete method accepts two parameters: The data type and id number of the object to be deleted.
Additional Notes:
Id numbers are used by the database to ensure that objects are put in the correct place and to allow the program to access these objects. It is important that programs using this library do not attempt to set these variables as they will be initialized and managed by the library. These id numbers are unique for objects of a given type; objects of different types may have the same id number. In addition, if objects are deleted from the database their id numbers are left empty and are not reused.
Licensing:
DataManagement is Currently Licensed under the GNU General Public License, version 3 (GPL-3.0). It is intended for open source use by anyone who would like to use it.

This is awesome!!
Tried it out for an app today-- incredibly simple! For those looking-- this library essentially replaces loads of SQL helper classes and queries with an interface that's similar to ArrayList.
Definitely going to use this for everything in the future!
Thanks

Did you change the license or something? The repo is no longer on github.

regaw_leinad said:
Did you change the license or something? The repo is no longer on github.
Click to expand...
Click to collapse
After a quick search on github, it looks like it's been moved here
https://github.com/epsilonlabsllc/DataManagement

cmike21 said:
After a quick search on github, it looks like it's been moved here
https://github.com/epsilonlabsllc/DataManagement
Click to expand...
Click to collapse
Thanks. I forgot to change it. I just edited my post with the correct url.

Sounds awesome! Great work.
Gonna try it this evening.

Anyone compared the performance with db4o?

are there any performance test with other DB libraries for android? and what about the this lib vs contentproviders?
activeandroid.com
code.google.com/p/orm-droid]orm-droid
satyan.github.com/sugar/

will definitly be using this once i learn some app development! thanks for this!

Just in time...

Hello,
I'm trying to build a simple project the test and learn how this lib works, but I'me quite new in programming and I have some difficulties to understand how to use dm.
The project will be a simple song database with edittexts for song and artist. I created the storableClass as the example, but I cannot understand how to connect it with the main activity, so I can use the output of the editTexts.
1st question is: do I need to have the String variables as private? I'm thinking that must have them as public, so I can connect them with the editTexts output.
2nd: question: all these methods needed to be called from storableClass, or from main activity, after I connected the storableClass with main activity? And how I do this?
Probably with the use of context you descibed, but I cannot understand how to do it. I tried sometimes but always get errors and a specific one "The constructor DataManager(Context) is not visible".
Is there any example project' source code which use this lib to get an Idea, or can you explain the context step more extensively?
Thanks in advance and sorry for noob questions.

dancer_69 said:
Hello,
I'm trying to build a simple project the test and learn how this lib works, but I'me quite new in programming and I have some difficulties to understand how to use dm.
The project will be a simple song database with edittexts for song and artist. I created the storableClass as the example, but I cannot understand how to connect it with the main activity, so I can use the output of the editTexts.
1st question is: do I need to have the String variables as private? I'm thinking that must have them as public, so I can connect them with the editTexts output.
2nd: question: all these methods needed to be called from storableClass, or from main activity, after I connected the storableClass with main activity? And how I do this?
Probably with the use of context you descibed, but I cannot understand how to do it. I tried sometimes but always get errors and a specific one "The constructor DataManager(Context) is not visible".
Is there any example project' source code which use this lib to get an Idea, or can you explain the context step more extensively?
Thanks in advance and sorry for noob questions.
Click to expand...
Click to collapse
Here is a sample project: https://github.com/epsilonlabsllc/D.../net/epsilonlabs/datamanagementefficient/test
(It's in the github project.)
You can set the strings on private, because you can grab the values of the edittext on your layout. Eclipse should generate your set/ get methods if you create your private strings. The methods. Take the values and insert them into your db, Look at the sample:
Code:
public DataSample(){
num1 = 3;
numderp = 3.0;
num3 = "three";
num4 = true;
ds2depier = new ArrayList<DataSample2>();
ds2depier.add(new DataSample2());
ds2depier.add(new DataSample2());
}
That is the basic constructor of the DataSample class. If you do an insert like
int id = dm.add(new StorableClass());
Click to expand...
Click to collapse
The basic constructor will be called and it sets your values for example the num1 =3. You could overwrite the basic constructor with your costum constructor to insert your values.
You activity call:
dm.add(DataSample(sSong,sTitle));
Click to expand...
Click to collapse
The constructor could be something like this:
public DataSample(String sSong, String sTitle){
sYourTitleDataBaseColumnCaption = sTitle;
sYourSongDataBaseColumnCaption = sSong;
}
Click to expand...
Click to collapse
Or use the set/get methods, my custom constructor are just an idea to show you an example. Just take a closer look at the github sample and it should work for you.

Thanks, I think I can figure it out now.

How to is very outdated. I can't initialize via new DataManager() but via getInstance(), also delete and update method doesn't have Id argument anymore.
Also,
I can't get this to work. I can't even add a member to collection because it needs to use db.add(new MyClass()); but i already have MyClass() initialized with their members. I have tried to do something like copy the Id from add, update into my other instance of this class and run a db.update() but it throws a RuntimeException.
Not usable at this time.

Sounds good!
I'll give it a try as soon as I start a new project that requires data storage ...
I really hate SQLiteOpenHelper, cursor and all this strange syntax ...

The idea is good, but it can't be compared to db4o, specially when talking about documentation.

Hello mate,
I'd like to use your library and backup the data with Google/Dropbox Sync... can you tell me the name of the file on which you save data?
Thanks,
Tiwiz

ID resource in Android XML

Hi
In the tutorial that i am reading says :
Any View object may have an integer ID associated with it, to uniquely identify the View within
the tree. When the application is compiled, this ID is referenced as an integer, but the ID is
typically assigned in the layout XML file as a string, in the id attribute. This is an XML attribute
common to all View objects (defined by the View class) and you will use it very often. The
syntax for an ID, inside an XML tag is:
android:id="@+id/my_button"
The at-symbol (@) at the beginning of the string indicates that the XML parser should parse and
expand the rest of the ID string and identify it as an ID resource . The plus-symbol (+) means that
this is a new resource name that must be created and added to our resources (in the R.java file).
My question is this : In phrase ID resource , the resource word what does mean ???
I know about resources in Android a little but i guess that the ID resource is different from that . Please give me help
Thanks for your helps

All data from xml files (like layouts, menus, etc.) is called resource because it's not Java. In Java all resources can be accessed using the R class.
As you need to access the ids as well (for access to the Views), they are added to the R.java file.
So you're right. It's different from layout/menu/color/string resources. I guess that it's just due to the Java access.

Uninitialized AudioRecord error

Hi,
I'm a hardware programmer who is new to the Android programmer world and I'm running into a bit of a weird issue. I'm trying to make an app that transmits and receives data through the 3.5mm audio jack. I have one app that runs perfectly and in order to create the new app I just transplanted the code into the new app. I've made very few alterations to the main activity class and the layout.xml to change the view, but now I get the error "startRecording() called on an uninitialized AudioRecord." I've been unable to figure out why the system thinks that the audioRecord is uninitialized. I've even gone so far as to move the initialization of the audioRecord to the line immediately preceding the call to start the recording. The initialization code is as follows:
Code:
_audioRecord = new AudioRecord(MediaRecorder.AudioSource.DEFAULT,
_sampleFrequency, AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT, recBufferSize);
_audioRecord.startRecording();
the error occurs at the line _audioRecord.startRecording();
Why would this work in one app and not in another? What could be causing this? Any help would be greatly appreciated. Thank you in advance,
-Chris

Registering devices with GCM error

Hello everybody,
I'm experimenting with Google Cloud Messaging and I was following the tutorial at https :// github. com/ GoogleCloudPlatform/gradle-appengine-templates/blob/master/GcmEndpoints/README.md (I beg pardon but I can't post links). Unfortunately I spent the last two days struggling with solving all the dependencies but I still miss one.
In this code (taken from the tutorial at point 2.2) I cannot resolve the class "Registration"; I've been trying looking for it but given such a vague name I got back millions results that had little to do with my problem.
I also tried to add to my project all the suggested libraries but none of them contained the class I need.
Code:
public GcmRegistrationAsyncTask() {
Registration.Builder builder = new Registration.Builder(AndroidHttp.newCompatibleTransport(), new AndroidJsonFactory(), null)
// Need setRootUrl and setGoogleClientRequestInitializer only for local testing, otherwise they can be skipped
.setRootUrl("h t t p : / / 10.0.2.2:8080/_ah/api/")
.setGoogleClientRequestInitializer(new GoogleClientRequestInitializer() {
@Override
public void initialize(AbstractGoogleClientRequest<?> abstractGoogleClientRequest) throws IOException {
abstractGoogleClientRequest.setDisableGZipContent(true);
}
});
// end of optional local run code
regService = builder.build();
}
Could somebody point me in the right direction?
Thanks in advance for the help!
Bye
Mario

I was just following the same instructions today and I am experiencing the same problem unfortunately.

thvranken said:
I was just following the same instructions today and I am experiencing the same problem unfortunately.
Click to expand...
Click to collapse
Well, at least it means probably we are not dumb
At any rate if I should find something I'll post it here so it's available to whoever needs it and pls do the same...

Hmm.. I couldn't find a "Registration" class or import anywhere in their source code so it may be included in one of the dependencies, try checking your build.gradle files against the one given in their source code to check for the correct dependencies.
In any case, their method is (IMO) an extremely weird and complicated way of doing something very simple, if you haven't found the solution by Monday (when I should have more free time) I'll put together a package (including the html/php/MySQL server back-end files) with how I managed to do GCM messaging (which includes multicast messages)

Jonny said:
Hmm.. I couldn't find a "Registration" class or import anywhere in their source code so it may be included in one of the dependencies, try checking your build.gradle files against the one given in their source code to check for the correct dependencies.
In any case, their method is (IMO) an extremely weird and complicated way of doing something very simple, if you haven't found the solution by Monday (when I should have more free time) I'll put together a package (including the html/php/MySQL server back-end files) with how I managed to do GCM messaging (which includes multicast messages)
Click to expand...
Click to collapse
Hi Jonny, tnx for taking time and having a look! I checked the gradle file but it seemed everything in order...
At any rate I started studying better the code (I should have done it earlier actually) and noted that in the backend Android Studio created before a class with the methods I invoke in the app and before the declaration there is annotation:
Code:
@Api(name = "registration", version = "v1", namespace = @ApiNamespace(ownerDomain = "backend.rtalert.rt_finance.com", ownerName = "backend.rtalert.rt_finance.com", packagePath=""))
public class RegistrationEndpoint {
private static final Logger log = Logger.getLogger(RegistrationEndpoint.class.getName());
Now, searching on the web seems like I would somehow need to compile the backend module and import it as a lib into my app (despite is all within the same project). I imported both the zip file and the discovery one and then synced gradle, but still nothing.
Tomorrow after a few hours sleep I'll try again...
Good night
Mario

Ok apologies for being a bit late, life's been busier than I was expecting over the last few days...
Anyway, the web server files are all located in the following zip file >>> http://darkforest-roms.co.uk/Misc/AndroidGoogleColudMessaging.zip
There is also a table.txt file that contains the MySQL database base table I'm using - the setup is for an app for my school where the staff can send messages to individual year groups or to all year groups.
Assuming whatever webhosting service you are using has phpMyAdmin or similar you can just change the table columns in the table.txt file and import it. Then you need to go through register.php, update.php, possibly unregister.php and index.php to modify the website code to your specific application.
You will also need to edit the parameters in config.php for your Google API key and database name, user and password.
Thats it for the website side code, give me a couple of days to sort out the app-side java code, I need to modify some stuff in my current code before uploading it

Jonny said:
Ok apologies for being a bit late, life's been busier than I was expecting over the last few days...
Anyway, the web server files are all located in the following zip file >>> [
There is also a table.txt file that contains the MySQL database base table I'm using - the setup is for an app for my school where the staff can send messages to individual year groups or to all year groups.
Assuming whatever webhosting service you are using has phpMyAdmin or similar you can just change the table columns in the table.txt file and import it. Then you need to go through register.php, update.php, possibly unregister.php and index.php to modify the website code to your specific application.
You will also need to edit the parameters in config.php for your Google API key and database name, user and password.
Thats it for the website side code, give me a couple of days to sort out the app-side java code, I need to modify some stuff in my current code before uploading it
Click to expand...
Click to collapse
Hi Jonny, don't worry, I was quite busy these days myself, plus I really appeciate your help... In the weekend I'll set it up so I can test it and let you know...
Thanks again
Mario

[Q] Extract JSON data and display in ListView with Searchbox

Hi Everyone,
I am currently a very new starter in the Android App Development stage. I have tried to develop a ListView with Searchbox facility to search data that comes from a specific URL in the form of JSON data. I managed to understand displaying this data in ListView, but adding a search facility is something I'm struggling to grasp somehow.
The code attached is a reference code I am trying to tune before I move on to actually developing my app. However, it doesn't seem to work on the emulator, giving me the error that the MainActivity file has stopped working.
I am unsure if there is a fundamental error somewhere, and would be really grateful to get some advice on this. I have looked online and can't seem to find a good resource that explains merging ListView with JSON data effectively with a Searchbox.

ajitmenezes said:
Hi Everyone,
I am currently a very new starter in the Android App Development stage. I have tried to develop a ListView with Searchbox facility to search data that comes from a specific URL in the form of JSON data. I managed to understand displaying this data in ListView, but adding a search facility is something I'm struggling to grasp somehow.
The code attached is a reference code I am trying to tune before I move on to actually developing my app. However, it doesn't seem to work on the emulator, giving me the error that the MainActivity file has stopped working.
I am unsure if there is a fundamental error somewhere, and would be really grateful to get some advice on this. I have looked online and can't seem to find a good resource that explains merging ListView with JSON data effectively with a Searchbox.
Click to expand...
Click to collapse
You should implement the search on the listview adapter, not on the activity itself.
Take a look at the following article:
http://www.mokasocial.com/2010/07/arrayadapte-filtering-and-you/