working with databases in android

Software Engineering Large Practical

Working with databases in Android

Stephen Gilmore

School of Informatics, University of Edinburgh

October 17th, 2012

Stephen Gilmore Software Engineering Large Practical

A database example

In this lecture we will look at an example Android applicationwhich creates a database of TODO notes, with reminders of thingswhich need to be done, and descriptions of these.

The application is due to Lars Vogel (http://www.vogella.com).


http://www.vogella.com

Lars Vogel example: TODOs

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A database example

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TodoDatabaseAdapter

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TodoDatabaseHelper (onCreate())

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TodoDatabaseHelper (onUpgrade())

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TodoDatabaseAdapter (open(), close())

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The create, update, and delete methods

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The insert() method

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The update() method

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The delete() method

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Fetch data

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Create content values

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Resources

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Running the application

When we run the application we are able to create a TODO note,and set its category to Urgent or Reminder.


Running the TODOs application

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Editing a TODO item


Setting category to “Urgent”


TODOs application code

We look at the application code to see how the Java code interactswith the XML layout and see how the database state is managed.


TodoDetails (imports)

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TodoDetails (onCreate)

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Graphical layout of todo edit.xml

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Text of todo edit.xml

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Outline of todo edit.xml

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TodoDetails (populateFields)

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Save state, onPause, onResume

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Save state

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TodosOverview (onCreate)

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Options menu, item selected

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Options item selected

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Accessing the insert menu

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Inspecting the database

During development we might have bugs in our code which causeproblems with the database. In this case we would like to be ableto see the content of the database and check that it is as weexpect. We can use the Dalvik Debug Monitor Server (DDMS) todo this and we can also inspect the database using other tools forprocessing SQLlite databases.


Dalvik Debug Monitor Server (DDMS)

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File explorer in DDMS

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/data/data/de.vogella.android.todos/...

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Pulling a file from the device

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Pulling a file from the device

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Get the device file

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Inspecting the file with sqlite3

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Inspecting the file with sqlite3 on DiCE

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Other tools for inspecting the database

Numerous browsers exist for SQLite databases.

I The CellObject SQLite & XML Browser is an Eclipseplug-in tool built on top of Dalvik Debug Monitor Server(DDMS), intended for Android application developers. It isavailable from http://cellobject.net/

I SQLite Manager is an add-on for Firefox which allows usersto browse SQLite databases using the Firefox browser. It isavailable from https://addons.mozilla.org/en-US/

firefox/addon/sqlite-manager/

I SQLite Database Browser allows users to create, design andedit database files compatible with SQLite using a familiarspreadsheet-like interface. It is available fromhttp://sqlitebrowser.sourceforge.net/


http://cellobject.net/

https://addons.mozilla.org/en-US/firefox/addon/sqlite-manager/

https://addons.mozilla.org/en-US/firefox/addon/sqlite-manager/

http://sqlitebrowser.sourceforge.net/

Using LogCat

As usual, the effect of Java exceptions and other problems willappear in the LogCat view.


Debugs and errors displayed in LogCat

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Can filter messages displayed in LogCat

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Can use view menu to export messages

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working with databases in android

Education

database state

database of todo notes

sqlite databases

example android application

database numerous browsers

sqlite manager

todos application codewe

android application