![]() You might have the following in your upgrade section of your app: db.execSQL(drop + Books.TABLE_BOOKS) It’s worth noting that this solution will not work well for changing of table names. It is also the solution that the Android Developer Documentation states. When the user upgraded, the “cache” would disappear and they would have to download all the data again. We weren’t storing user data our database was just a cache of things from the network. Sure, when we started development this was obviously the easiest approach. These are the solutions that we went through: Solution 1: Delete the tables that have changed and recreate them I’ve been there and battled the fires in production. Upgrading databases in Android is difficult. When using your own SQLite database in Android, most people take for granted future releases of the application they are working on. Looking at the Android Developer documentation can also lead you down a rickety path. The post explains quite well the drawbacks of some of the solutions that I also went through, but their final solution can also leave you in trouble. ![]() Import reading this blog post (and a few others) on how to use the onUpgrade() method for your Android SQLite Database, I thought I should share my experience about how to correctly upgrade your database. It will also be beneficial to highlight why the final solution listed in that blog post would also fail at some point for some scenarios. Run the application and choose a running android device and install the application on it and verify the results.įollowing is the content of the modified MainActivity.java. Modify the res/menu/display_contact.xml to add necessary menu componentsĬreate a new menu as res/menu/mainmenu.xml to add the insert contact option ![]() Modify the res/values/string.xml to add necessary string components Modify the res/layout/activity_display_contact.xml to add respective XML components Modify the res/layout/activity_main to add respective XML components Modify src/MainActivity.java file to get references of all the XML components and populate the contacts on listView.Ĭreate new src/DBHelper.java that will manage the database workĬreate a new Activity as Displa圜ontact.java that will display the contact on the screen You will use Android studio to create an Android application under a package. To experiment with this example, you need to run this on an actual device on which camera is supported. It creates a basic contacts applications that allows insertion, deletion and modification of contacts. Here is an example demonstrating the use of SQLite Database. Public class DBHelper extends SQLiteOpenHelper It automatically manages the creation and update of the database. This method returns true if the cursor is closed and return false otherwiseįor managing all the operations related to the database, an helper class has been given and is called SQLiteOpenHelper. This method returns the current position of the cursor in the table This method returns the total number of rows in the cursor This method returns the array of all the column names of the table. This method returns the name of the column by specifying the index of the column This method returns the index number of a column by specifying the name of the column This method return the total number of columns of the table. Another method that also does the same job but take some additional parameter is given below This will insert some values into our table in our database. Mydatabase.execSQL("INSERT INTO TutorialsPoint VALUES('admin','admin') ") Mydatabase.execSQL("CREATE TABLE IF NOT EXISTS TutorialsPoint(Username VARCHAR,Password VARCHAR) ") We can create table or insert data into table using execSQL method defined in SQLiteDatabase class. This method is similar to above method but it takes the File object as a path rather then a string. OpenOrCreateDatabase(File file, SQLiteDatabase.CursorFactory factory) This method is equivalent to openDatabase method. It not only opens but create the database if it not exists. OpenOrCreateDatabase(String path, SQLiteDatabase.CursorFactory factory) It is similar to the above method as it also opens the existing database but it does not define any handler to handle the errors of databases OpenDatabase(String path, SQLiteDatabase.CursorFactory factory, int flags) The common flags mode could be OPEN_READWRITE OPEN_READONLY This method only opens the existing database with the appropriate flag mode. OpenDatabase(String path, SQLiteDatabase.CursorFactory factory, int flags, DatabaseErrorHandler errorHandler)
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