Sqlitedatabase implements access to SQLite

Access to the SQLite database via Sqlitedatabase

----Main.java

public class main extends activity {sqlitedatabase db; listview listview; edittext edittext1, edittext2;  //the title and contextbutton button; to add @Overrideprotected  void oncreate (bundle savedinstancestate)  {super.oncreate (savedInstanceState); Setcontentview (R.layout.main);listview =  (ListView)  findviewbyid (r.id.listview1); editText1  =  (EditText)  findviewbyid (R.ID.EDITTEXT1);edittext2 =  (EditText)  findviewbyid ( R.ID.EDITTEXT2);button =  (Button)  findviewbyid (r.id.button1);// /data/data/ Com.example.dbtest/files --/my.db3  db = sqlitedatabase.openorcreatedatabase ( This.getfilesdir (). toString () +  "/my.db3",  null); Button.setonclicklistener (New onclicklistener ()  {@Overridepublic  void onclick (view v)  {String str1 =  Edittext1.gettext (). toString (); String str2 = edittext2.getteXT (). toString (); Try {inserttodb (DB, STR1, STR2); Cursor cursor = db.rawquery ("Select * from news_info", null); InflateListView ( cursor);}  catch  (sqliteexception e)  {db.execsql ("Create table news_info (_id integer  primary key autoincrement, "+ " News_title varchar (a), "+ " news_content  varchar (255)); Inserttodb (DB, STR1, STR2); Cursor cursor = db.rawquery ("Selecte * from news_info", null); InflateListView ( cursor);}});} Private void inserttodb (SQLITEDATABASE DB, STRING STR1, STRING STR2)  { Db.execsql ("Insert into news_info values (null, ?, ?)",  new string[] { str1, str2 });} Private void inflatelistview (cursor cursor)  {SimpleCursorAdapter adapter =  New simplecursoradapter (Main.this,r.layout.item, cursor, new&nbsP string[] {  "News_title", "News_content"  }, new int[] { r.id.textview1, R.id.textview2 },cursoradapter.flag_register_content_observer); Listview.setadapter (adapter);} @Overrideprotected  void ondestroy ()  {super.ondestroy (); if (Db!=null&&db.isopen ()) { Db.close ();}}}

Simplecursoradapter the cursor is encapsulated, the column name that requires the primary key column of the data table is _id. Because the Simplecursoradapter can only recognize columns named

The primary key of the _id. Otherwise you will get an error.

As with the Java operation JDBC, the database is finally closed db.close (); to reclaim resources.

---main.xml

<relativelayout xmlns:android= "Http://schemas.android.com/apk/res/android"      xmlns:tools= "Http://schemas.android.com/tools"     android:layout_width= "Match_parent"     android:layout_height= "Match_parent"     tools:context= "${ Relativepackage}.${activityclass} " >    <EditText         android:id= "@+id/edittext1"         android:layout_ Width= "Wrap_content"         android:layout_height= "Wrap_content"          android:layout_alignparentleft= "true"          android:layout_alignparenttop= "true"         android: Ems= "Ten"  >        <requestFocus />     </edittext> &Nbsp;  <edittext        android:id= "@+id/editText2"          android:layout_width= "Wrap_content"          android:layout_height= "Wrap_content"         android: Layout_alignparentleft= "true"         android:layout_below= "@+id/ EditText1 "        android:ems="  />     <button        android:id= "@+id/button1"          android:layout_width= "Wrap_content"          android:layout_height= "Wrap_content"         android:layout_ Alignparentleft= "true"         android:layout_below= "@+id/editText2"         android:text= "Inserting data"  />    <ListView         android:id= "@+id/listview1"         android:layout_width= " Match_parent "        android:layout_height=" Wrap_content "         android:layout_alignparentleft= "true"          android:layout_below= "@+id/button1"  >    </listview></ Relativelayout>

Listeview the layout file for each subkey Item.xml:

<?xml version= "1.0"  encoding= "Utf-8"? ><relativelayout xmlns:android= "http// Schemas.android.com/apk/res/android "    android:layout_width=" Match_parent "     android:layout_height= "Match_parent"  >    <TextView         android:id= "@+id/textview1"          android:layout_width= "Wrap_content"         android:layout_height = "Wrap_content"         android:layout_alignparentleft= "true"          android:layout_alignparenttop= "true"          android:text= "TextView"  />    <TextView         android:id= "@+id/textview2"          Android:layout_width= "Wrap_content"         android:layout_height= "Wrap_content"          android:layout_alignparenttop= "true"         android:layout _marginleft= "20DP"         android:layout_torightof= "@+id/textView1"         android:text= "TextView"  /></RelativeLayout>

Operating effect:

Sqlitedatabase implements access to SQLite