Android database Android comes with database SQLite operation step by step diagram tutorial

Source: Internet
Author: User

The use of Android in the development process of the database, not only better security, but also the effect of data access is better.

Attached source code

http://download.csdn.net/detail/wyx100/8670843

Development planning Main Interface

Complete input of data, trigger save

Post-boot interface

Input data

Data Display Interface

The database is displayed after reading the data

Deleting records

Development Sequence Main interface

Class Code

Package Com.example.sqlitetest;import Android.os.bundle;import Android.app.activity;import Android.content.contentvalues;import Android.content.intent;import Android.view.view;import Android.widget.Button Import Android.widget.edittext;public class Activitymain_1 extends Activity {//Declaration EditText Instance Private EditText Et1,et2, et3;//declaring a Button instance private button button; @Overrideprotected void OnCreate (Bundle savedinstancestate) {//TODO Auto-generated method Stubsuper.oncreate (savedinstancestate); Setcontentview (r.layout.main_1);//Get instance Object Et1 = ( EditText) Findviewbyid (r.id.edittext01) Et2 = (EditText) Findviewbyid (r.id.edittext02); et3 = (EditText) Findviewbyid ( r.id.edittext03), Button = (button) Findviewbyid (R.id.button);//Event Button.setonclicklistener (new View.onclicklistener () {@Overridepublic void OnClick (View v) {String name=et1.gettext (). toString (); String URL =et2.gettext (). toString (); String desc = Et3.gettext (). toString (); Contentvalues values = new Contentvalues (); Values.put ("name", name); valueS.put ("url", url); Values.put ("desc", desc);//Instantiate Database helper class DBHelper helper = new DBHelper (Getapplicationcontext ());// Open database Helper.open (); Insert data Helper.insert (values);//Instantiate intentintent intent = new Intent (Activitymain_1.this,queryactivity.class); StartActivity (intent); Helper.close ();}});}}

Interface layout
<?xml version= "1.0" encoding= "UTF-8"? ><linearlayout xmlns:android= "http://schemas.android.com/apk/res/ Android "android:orientation=" vertical "android:layout_width=" fill_parent "android:layout_height=" Fill_parent " ><textviewandroid:id= "@+id/textview01" android:layout_width= "fill_parent" android:layout_height= "Wrap_ Content "android:text=" site name "/><edittextandroid:id=" @+id/edittext01 "android:layout_width=" Fill_parent " android:layout_height= "Wrap_content"/><textviewandroid:id= "@+id/textview02" android:layout_width= "Fill_ Parent "android:layout_height=" wrap_content "android:text=" URL "/><edittextandroid:id=" @+id/EditText02 " Android:layout_width= "Fill_parent" android:layout_height= "wrap_content"/><textviewandroid:id= "@+id/ TextView03 "android:layout_width=" fill_parent "android:layout_height=" wrap_content "android:text=" site description "/>< Edittextandroid:id= "@+id/edittext03" android:layout_width= "fill_parent" android:layout_height= "Wrap_content" android:height= "100px"/><buttonAndroid:id= "@+id/button" android:layout_width= "wrap_content" android:layout_height= "Wrap_content" android:text= " Add the/></linearlayout>

2. Data Display Interface

Class Code

Package Com.example.sqlitetest;import Android.app.alertdialog;import Android.app.listactivity;import Android.content.dialoginterface;import Android.database.cursor;import Android.os.bundle;import Android.view.View; Import Android.widget.adapterview;import Android.widget.adapterview.onitemclicklistener;import Android.widget.listview;import Android.widget.simplecursoradapter;public class Queryactivity extends ListActivity { Private ListView listview;private Cursor C; @Overrideprotected void OnCreate (Bundle savedinstancestate) {//TODO auto-generated method Stubsuper.oncreate ( Savedinstancestate);//setcontentview (r.layout.row);//Instantiate Database Helper class final DBHelper help = new DBHelper (this); Help.open (); C= Help.query (); Query ();//Hint Dialog final Alertdialog.builder Builder = new Alertdialog.builder (this); Listview.setonitemclicklistener ( New Onitemclicklistener () {@Overridepublic void Onitemclick (adapterview<?> parent, View view,int position, long ID {Final Long temp = Id;builder.setmessage ("Do you really want to delete this record?"). ").Setpositivebutton ("Yes", new Dialoginterface.onclicklistener () {@Overridepublic void OnClick (Dialoginterface dialog, int which) {System.out.println ("yes"), Help.del ((int) temp);//Requery//query (); Cursor C = help.query ();//list item array string[] from ={"_id", "name", "url", "desc"};//list item idint[] to ={R.ID.TEXT0,R.ID.TEXT1, r.id.text2,r.id.text3};//Adapter Simplecursoradapter adapter = new Simplecursoradapter (Getapplicationcontext (), R.LAYOUT.ROW,C,FROM,TO); ListView ListView = Getlistview (); Listview.setadapter (adapter);}}). Setnegativebutton ("No", new Dialoginterface.onclicklistener () {@Overridepublic void OnClick (Dialoginterface dialog, int which) {//TODO auto-generated Method stub}}); Builder.create (); Builder.show ();});} @Overrideprotected void OnStop () {//TODO auto-generated method Stubsuper.onstop ();} public void query () {//list item array string[] from ={"_id", "name", "url", "desc"};//list item idint[] to ={R.ID.TEXT0,R.ID.TEXT1, r.id.text2,r.id.text3};//Adapter Simplecursoradapter adapter = new Simplecursoradapter (THIS,R.LAYOUT.ROW,C,FROm,to);//adapter.notifydatasetchanged ();//List View ListView = Getlistview ();//Add Adapter Listview.setadapter for List view (adapter);}} 


Interface layout

<?xml version= "1.0" encoding= "UTF-8"? ><linearlayout xmlns:android= "http://schemas.android.com/apk/res/ Android "android:orientation=" horizontal "android:layout_width=" Fill_parent "android:layout_height=" Fill_parent " Android:layout_gravity= "center_vertical" ><textviewandroid:id= "@+id/text0" android:layout_width= "Wrap_ Content "android:layout_height=" wrap_content "android:paddingright=" 10px "/><textviewandroid:id=" @+id/text1 "Android:layout_width=" wrap_content "android:layout_height=" wrap_content "android:paddingright=" 10px "/>< Textviewandroid:id= "@+id/text2" android:layout_width= "wrap_content" android:layout_height= "Wrap_content" Android: paddingright= "10px"/><textviewandroid:id= "@+id/text3" android:layout_width= "Wrap_content" Android:layout_ height= "Wrap_content" android:paddingright= "10px"/></linearlayout>
Database processing Classes
Package Com.example.sqlitetest;import Android.content.contentvalues;import Android.content.context;import Android.database.cursor;import Android.database.sqlite.sqlitedatabase;import Android.database.sqlite.sqliteopenhelper;public class DBHelper extends Sqliteopenhelper {private static final String DB _name= "coll.db";//???? private static final String tbl_name= "logtable";//???? Sql??? private static final String create_tbl = "CREATE table logtable" + "(_id integer primary key autoincrement,name Text,url t Ext,desc text) ";//sqlitedatabase??? Private Sqlitedatabase Db;public DBHelper (context context) {Super (context, db_name, NULL, 2);} @Overridepublic void OnCreate (Sqlitedatabase db) {db.execsql (CREATE_TBL);} //?????? public void Open () {db = Getwritabledatabase ();} @Overridepublic void Onupgrade (sqlitedatabase db, int oldversion, int newversion) {//TODO auto-generated method stub}//?? ???? public void Insert (Contentvalues values) {Db.insert (tbl_name, null, values);} //??????? Public Cursor query () {CurSor C = db.query (tbl_name, NULL, NULL, NULL, NULL, NULL, NULL); return c;} //??? public void del (int id) {Db.delete (Tbl_name, "_id=?", new String[]{string.valueof (ID)}); //??????? public void Close () {if (db! = null) {Db.close ();}}}

Startup configuration file

Androidmanifest.xml

<?xml version= "1.0" encoding= "Utf-8"? ><manifest xmlns:android= "http://schemas.android.com/apk/res/        Android "package=" Com.example.sqlitetest "android:versioncode=" 1 "android:versionname=" 1.0 "> <uses-sdk android:minsdkversion= "8" android:targetsdkversion= "/> <application android:allowbackup=" "True" android:icon= "@drawable/ic_launcher" android:label= "@string/app_name" android:theme= "@style/ Apptheme "> <activity android:name=" com.example.sqlitetest.ActivityMain_1 "Android:labe L= "@string/app_name" > <intent-filter> <action android:name= "android.intent.action.m AIN "/> <category android:name=" Android.intent.category.LAUNCHER "/> </intent-filter > </activity> <activity android:name= "Com.example.sqlitetest.QueryActivity" ></a Ctivity> </application></manifest> 



Android database Android comes with database SQLite operation step by step diagram tutorial

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