SQLite instance--dummynote.java

Attach the source code first. Code is constantly updated in the main implementation of a Notepad function, involving SQLite crud operations.

Dummynote.java

Package Com.example.dummynote;import Android.os.bundle;import Android.support.v4.widget.SimpleCursorAdapter; Import Android.view.menu;import android.view.menuitem;import Android. R.bool;import Android.app.listactivity;import Android.database.cursor;import Android.widget.arrayadapter;import Android.widget.listadapter;public class Dummynote extends listactivity {@Overrideprotected void OnCreate (Bundle Savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (R.layout.main); GetListView (). Setemptyview (Findviewbyid (R.id.empty));//The display contents of empty text box Setadapter () When the set list is blank;} Private string[] note_array={/* "Hangsome", "Lushichuanshuo", "Android", "Library" */};p rivate notesdbadapter mdbhelper ;p rivate Cursor mnotecursor;private void Setadapter () {mdbhelper = new Notesdbadapter (this); Mdbhelper.open (); Filldata ( );} private void Filldata () {mnotecursor = Mdbhelper.getall (); Startmanagingcursor (mnotecursor); String[] from = new string[]{notesdbadapter.note};int[] to = new int[]{android. R.id.text1};//andrOid. R.ID.TEXT1 is an identifier for the TextView inside the Android framework//now create a simple cursor Adaptersimplecursoradapter adapter =new Simplecursoradapter (this, Android. R.layout.simple_list_item_1, Mnotecursor, from, to); Setlistadapter (adapter);} ADD a entityprivate int mnotenumber = 1;protected static final int menu_insert = Menu.first; @Overridepublic boolean ONCR Eateoptionsmenu (Menu menu) {//Inflate the menu; This adds items to the action bar if it is present. super.oncreateoptions Menu (menu); Menu.add (0,menu_insert, 0, "Add Notes"); return Super.oncreateoptionsmenu (menu);} public boolean onoptionsitemselected (MenuItem item) {switch (Item.getitemid ()) {case menu_insert:string notename = "Note "+ mnotenumber++;mdbhelper.create (notename); Filldata (); return true;} return super.onoptionsitemselected (item);}} <p></p>

Notesdbadapter.java<pre name= "code" class= "java" >package com.example.dummynote;import Java.util.Date;import Android.content.contentvalues;import Android.content.context;import Android.database.sqlexception;import Android.database.sqlite.sqlitedatabase;import Android.database.sqlite.sqliteopenhelper;import android.database.* Import Android.util.log;public class Notesdbadapter {private static final String TAG = "Notes";p rivate static final Strin G database_name = "Notes.db";p rivate static final int database_version = 1;p rivate static final String database_table = " Notes ";p rivate static final String database_create =" CREATE Table notes ("+" _id INTEGER PRIMARY KEY, "+" note TEXT not NULL, "+" created INTEGER "+"); "; private static class Databasehelper extends Sqliteopenhelper{public databasehelper (context context) {Super (context, database_name,null,database_version);//TODO auto-generated constructor stub} @Override//Create data table public void OnCreate ( Sqlitedatabase db) {//TODO auto-generated MethoD stubtry {db.execsql (database_create); LOG.D (TAG, "OnCreate!");} catch (Exception e) {log.d (TAG, e.tostring ());}} @Override//Update datasheet public void Onupgrade (sqlitedatabase db, int oldversion, int newversion) {try {//TODO auto-generated Meth Od stubdb.execsql ("DROP TABLE IF EXISTS" +database_table); onCreate (db); LOG.D (TAG, "inupgrade!");} catch (Exception e) {log.d (TAG, "Onupgrade failure!");}}} Private Context mctx = null; Abstract interface Private Databasehelper dbhelper; Database Tools class private Sqlitedatabase db; Database class/** Constructor**/public notesdbadapter (Context ctx) {this.mctx=ctx;} Public Notesdbadapter Open () throws Sqlexception{dbhelper = new Databasehelper (mctx);d B = Dbhelper.getwritabledatabase ( );//The database does not exist to create a, if there is a repository to decide whether to update the database return this;} public void Close () {dbhelper.close ();} public static final String ROWID = "_id";p ublic static final String note = "Note";p ublic static final String CREATED = "Created"; string[] Strcols = new string[]{rowid,note,created};//retrieved. The pointer is returned. Less memory public Cursor GetAll () {RETUrn Db.query (Database_table,//which TABLE to Selectstrcols,//which columns to Returnnull,//where Clausenull,//Where Argumentsnull,//group by Clausenull,//having clausenull//order-by clause);} Add public long Create (String Note) {Date now = new Date (); Contentvalues args = new Contentvalues (); Args.put (note, note); Args.put (CREATED, Now.getdate ()); return Db.insert ( Database_table, null, args);}}

SQLite instance--dummynote.java