Android SQLite Example

Question

I am new to Android and I have to create an application where I need to use a SQLite database  I am not so well equipped with the SQLite   Could you tell me what the purpose and use of the SQLiteOpenHelper class  and provide a simple database creation and insertion example

User · Answer

The DBHelper class is what handles the opening and closing of sqlite databases as well sa creation and updating  and a decent article on how it all works is here  When I started android it was very useful  however I ve been objective-c lately  and forgotten most of it to be any use

User · Answer

Using Helper class you can access SQLite Database and can perform the various operations on it by overriding the onCreate   and onUpgrade   methods   http   technologyguid com android-sqlite-database-app-example

User · Answer

Sqlite helper class helps us to manage database creation and version management  SQLiteOpenHelper takes care of all database management activities  To use it       1 Override onCreate    onUpgrade   methods of SQLiteOpenHelper  Optionally override onOpen   method      2 Use this subclass to create either a readable or writable database and use the SQLiteDatabase s four API methods insert    execSQL    update    delete   to create  read  update and delete rows of your table   Example to create a MyEmployees table and to select and insert records    public class MyDatabaseHelper extends SQLiteOpenHelper        private static final String DATABASE NAME    DBName        private static final int DATABASE VERSION   2          Database creation sql statement     private static final String DATABASE CREATE    create table MyEmployees                                     id integer primary key name text not null          public MyDatabaseHelper Context context            super context  DATABASE NAME  null  DATABASE VERSION                 Method is called during creation of the database      Override     public void onCreate SQLiteDatabase database            database execSQL DATABASE CREATE                 Method is called during an upgrade of the database       Override     public void onUpgrade SQLiteDatabase database int oldVersion int newVersion           Log w MyDatabaseHelper class getName                              Upgrading database from version     oldVersion     to                              newVersion      which will destroy all old data            database execSQL  DROP TABLE IF EXISTS MyEmployees            onCreate database             Now you can use this class as below   public class MyDB         private MyDatabaseHelper dbHelper         private SQLiteDatabase database         public final static String EMP TABLE  MyEmployees      name of table       public final static String EMP ID   id      id value for employee     public final static String EMP NAME  name       name of employee                           param context                public MyDB Context context             dbHelper   new MyDatabaseHelper context             database   dbHelper getWritableDatabase                  public long createRecords String id  String name             ContentValues values   new ContentValues              values put EMP ID  id             values put EMP NAME  name             return database insert EMP TABLE  null  values                    public Cursor selectRecords             String   cols   new String    EMP ID  EMP NAME             Cursor mCursor   database query true  EMP TABLE cols null                 null  null  null  null  null             if  mCursor    null                  mCursor moveToFirst                          return mCursor     iterate to get each value            Now you can use MyDB class in you activity to have all the database operations  The create records will help you to insert the values similarly you can have your own functions for update and delete

User · Answer

The following Links my help you  1  Android Sqlite Database  2  Tutorial 1  Database Helper Class   A helper class to manage database creation and version management   You create a subclass implementing onCreate SQLiteDatabase   onUpgrade SQLiteDatabase  int  int  and optionally onOpen SQLiteDatabase   and this class takes care of opening the database if it exists  creating it if it does not  and upgrading it as necessary  Transactions are used to make sure the database is always in a sensible state   This class makes it easy for ContentProvider implementations to defer opening and upgrading the database until first use  to avoid blocking application startup with long-running database upgrades    You need more refer this link Sqlite Helper

[android] Android SQLite Example

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