Programmatically use the SQLite database to perform crud (create read update delete) operations

Dbadapter Database Helper Classes

 Packagecom.databses; Importandroid.content.ContentValues; ImportAndroid.content.Context; ImportAndroid.database.Cursor; Importandroid.database.SQLException; Importandroid.database.sqlite.SQLiteDatabase; ImportAndroid.database.sqlite.SQLiteOpenHelper; ImportAndroid.util.Log;  Public classDbadapter {Static FinalString Key_rowid = "_id"; Static FinalString key_name = "NAME"; Static FinalString key_email = "EMAIL"; Static FinalString TAG = "Dbadapter"; Static FinalString database_name = "MyDB"; Static FinalString database_table = "Contacts"; Static Final intDatabase_version = 1; Finalcontext Context; //To create a table SQL statement    Static FinalString database_create = "CREATE table Contacts (_id integer primary key autoincrement,name text not null,email text not n ULL) ";      Sqlitedatabase DB;            Databasehelper DBHelper;  PublicDbadapter (Context context) { This. Context =context; DBHelper=NewDatabasehelper (context); }            //Database helper class inheritance Sqliteopenhelper    Private Static classDatabasehelperextendssqliteopenhelper{ PublicDatabasehelper (Context context) {Super(Context, database_name,NULL, database_version); }            //Create a database@Override Public voidonCreate (Sqlitedatabase db) {Try{db.execsql (database_create); } Catch(Exception e) {e.printstacktrace (); }          }          //upgrading the database version@Override Public voidOnupgrade (Sqlitedatabase db,intOldversion,intnewversion) {LOG.W (TAG,"Upgrading db from Version" +oldversion+ "to" +newversion+ ", which'll destory all old data"); Db.execsql ("DROP table if exists contacts");          OnCreate (DB); }      }            //Open Database     PublicDbadapter Open ()throwsSQLException {db=dbhelper.getwritabledatabase (); return  This; }            //Close the database     Public voidClose () {dbhelper.close (); }            //insert a Contact record     Public Longinsertcontact (String name,string email) {contentvalues Initalvalues=Newcontentvalues ();          Initalvalues.put (Key_name,name);          Initalvalues.put (Key_email, EMAIL); returnDb.insert (Database_table,NULL, initalvalues); }            //Delete a record     Public BooleanDeleteContact (LongrowId) {          returnDb.delete (database_table,key_rowid+ "=" +rowid,NULL) >0; }            //Find all Contacts     PublicCursor getallcontacts () {returnDb.query (Database_table,NewString[]{key_rowid,key_name,key_email},NULL,NULL,NULL,NULL,NULL,NULL); }            //Query a record     PublicCursor GetContact (LongROWID)throwssqlexception{cursor Cursor= Db.query (true, Database_table,NewString[]{key_rowid,key_name,key_email}, key_rowid+ "=" +rowid,NULL,NULL,NULL,NULL,NULL); if(Cursor! =NULL) {Cursor.movetofirst (); }          returncursor; }            //Update a contact     Public BooleanUpdatecontact (Longrowid,string name,string Email) {contentvalues contentvalues=Newcontentvalues ();          Contentvalues.put (Key_name, NAME);          Contentvalues.put (Key_email, EMAIL); returnDb.update (database_table, contentvalues, key_rowid+ "=" +key_rowid,NULL) >0; }  }  

Databaseactivity

 Packagecom.databses; ImportAndroid.os.Bundle; Importandroid.app.Activity; ImportAndroid.view.Menu;  Public classDatabasesactivityextendsActivity {@Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);          Setcontentview (r.layout.activity_databases); Dbadapter Dbadapter=NewDbadapter ( This);          Dbadapter.open (); Dbadapter.insertcontact ("Weiwei", "[email protected]"); Dbadapter.insertcontact ("Jackson", "[email protected]"); }      }