Android Database Operations

Package Cn.hackcoder.beautyreader.db;import Android.content.context;import Android.database.sqlite.SQLiteDatabase ; Import Android.database.sqlite.sqliteopenhelper;import android.util.log;/** * Created by Hackcoder on 15-1-25.    */public class Databasehelper extends Sqliteopenhelper {private static final String DbName = "sample.db";    private static int dbversion = 1;    Public Databasehelper (Context context) {super (context,dbname,null,dbversion);        } @Override public void OnCreate (Sqlitedatabase db) {log.d ("===========", "Database Initialization"); Build table String sql = "CREATE table if not exists tb_article (ID integer PRIMARY key autoincrement,title varchar (), con        Tent Text,url varchar (+), page integer) ";    Db.execsql (SQL); }/** * * @param db * @param oldversion * @param newversion */@Override public void Onupgrad E (sqlitedatabase db, int oldversion, int newversion) {}}

Package Cn.hackcoder.beautyreader.service;import Android.content.context;import Android.database.cursor;import Android.database.sqlite.sqlitedatabase;import Java.util.arraylist;import Java.util.list;import Cn.hackcoder.beautyreader.db.databasehelper;import cn.hackcoder.beautyreader.model.article;/** * Created by Hackcoder on 15-1-25.    */public class Articleservice {private Databasehelper databasehelper;    Private Sqlitedatabase readabledatabase;    Private Sqlitedatabase writabledatabase;    Public Articleservice (Context context) {Databasehelper = new Databasehelper (context); } public void Add (article article) {String sql = ' INSERT INTO tb_article (id,title,content,url,page) VALUES (?,?,        ?,?,?)"; Getreadabledatabase (). Execsql (SQL, New Object[]{null, Article.gettitle (), Article.getcontent (), Article.geturl (),    Article.getpage ()});        } public void Delete (int id) {String sql = ' Delete from tb_article where id =? '; Getreadabledatabase (). ExecsQL (SQL, new Object[]{id});        } public void DeleteAll () {String sql = ' delete from tb_article ';    Getreadabledatabase (). Execsql (Sql,null); } public void update (article article) {String sql = "Update tb_article set title=?,content=?,url=?,page =?        WHERE id =? "; Getreadabledatabase (). Execsql (SQL, New Object[]{article.gettitle (), Article.getcontent (), Article.geturl (),    Article.getpage (), Article.getid ()}); } public void Updatecontentofurl (string url,string content) {String sql = "Update tb_article set content=?        Where url =? ";    Getreadabledatabase (). Execsql (SQL, new Object[]{content,url});        } public article find (int id) {Article Article = new article ();        String sql = "Select Id,title,content,url,page from tb_article where id =?";        cursor cursor = Getreadabledatabase (). Rawquery (SQL, new string[]{string.valueof (ID)});            if (Cursor.movetonext ()) {Article.setid (ID); Article.settitle (CURsor.getstring (Cursor.getcolumnindex ("title")));            Article.setcontent (Cursor.getstring (Cursor.getcolumnindex ("content"));            Article.seturl (Cursor.getstring (cursor.getcolumnindex ("url"));            Article.setpage (Cursor.getint (Cursor.getcolumnindex ("page"));            Cursor.close ();        return article;        } cursor.close ();    return null; } public list<article> findbyurl (String url) {list<article> articles = new arraylist<article>        ();        String sql = "Select Id,title,content,url,page from tb_article where url =?";        cursor cursor = Getreadabledatabase (). Rawquery (SQL, new String[]{url});            while (Cursor.movetonext ()) {Article Article = new article ();            Article.setid (Cursor.getint (Cursor.getcolumnindex ("id")));            Article.settitle (Cursor.getstring (Cursor.getcolumnindex ("title"));       Article.setcontent (Cursor.getstring (Cursor.getcolumnindex ("content"));     Article.seturl (Cursor.getstring (cursor.getcolumnindex ("url"));            Article.setpage (Cursor.getint (Cursor.getcolumnindex ("page"));        Articles.add (article);        } cursor.close ();    return articles;        } public int getcountofpage (int page) {String sql = ' SELECT COUNT (*) from tb_article where page =? ";        cursor cursor = Getreadabledatabase (). Rawquery (SQL, New String[]{string.valueof (page)});        Cursor.movetofirst ();        int count = cursor.getint (0);        Cursor.close ();    return count; } public list<article> getarticlesofpage (int curpage) {list<article> articles = new Arraylist<art        Icle> ();        String sql = "Select Id,title,content,url,page from tb_article where page =?";        cursor cursor = Getreadabledatabase (). Rawquery (sql,new string[]{string.valueof (Curpage)});            while (Cursor.movetonext ()) {Article Article = new article (); Article.setid (Cursor.getint (cursor. Getcolumnindex ("id")));            Article.settitle (Cursor.getstring (Cursor.getcolumnindex ("title"));            Article.setcontent (Cursor.getstring (Cursor.getcolumnindex ("content"));            Article.seturl (Cursor.getstring (cursor.getcolumnindex ("url"));            Article.setpage (Cursor.getint (Cursor.getcolumnindex ("page"));        Articles.add (article);        } cursor.close ();    return articles;        } public int countofsum () {String-sql = "SELECT COUNT (*) from tb_article";        cursor cursor = Getreadabledatabase (). rawquery (sql, NULL);        Cursor.movetofirst ();        int count = cursor.getint (0);        Cursor.close ();    return count; } public list<article> getarticles (int start, int pageSize) {list<article> articles = new ArrayList        <Article> ();        String sql = "Select Id,title,content,url,page from Tb_article limit?,?"; cursor cursor = Getreadabledatabase (). Rawquery (Sql,new String[]{string.valueOf (start), string.valueof (PageSize)});            while (Cursor.movetonext ()) {Article Article = new article ();            Article.setid (Cursor.getint (Cursor.getcolumnindex ("id")));            Article.settitle (Cursor.getstring (Cursor.getcolumnindex ("title"));            Article.setcontent (Cursor.getstring (Cursor.getcolumnindex ("content"));            Article.seturl (Cursor.getstring (cursor.getcolumnindex ("url"));            Article.setpage (Cursor.getint (Cursor.getcolumnindex ("page"));        Articles.add (article);        } cursor.close ();    return articles; } public void Closedb () {if (readabledatabase! = null && readabledatabase.isopen ()) {Readab        Ledatabase.close ();        } if (writabledatabase! = null && writabledatabase.isopen ()) {writabledatabase.close ();    }} public Sqlitedatabase Getreadabledatabase () {return databasehelper.getreadabledatabase (); } public SqlitedatabaseGetwritabledatabase () {return databasehelper.getwritabledatabase (); }}

Android Database Operations