Android 如何對sqlite數據庫進行增刪改[insert、update和delete] 操作

在android開發中，我們常常用sqlite來存儲用戶信息，如何進行sqlite常規操作呢，請參閱下面的示例代碼：

package com.db.imgfornote;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBHelper extends SQLiteOpenHelper {
    final private static String mDbName="imgfornote";
    final private static int mDbVersion=1;
    private static DBHelper mInstance=null;
    private final static String mTUserPhoto="UserPhoto";
    final private static String mCreateSqlForNoteClass="create table if not exists NoteClass(classId integer primary key asc autoincrement,className NVARCHAR(100),rowTime timestamp default (datetime('now', 'localtime')))";
    final private static String mCreateSqlForUserPhoto="create table if not exists UserPhoto(photoId integer primary key asc autoincrement,photoName VARCHAR(200),userPt VARCHAR(200),title VARCHAR(255),classId integer,content NVARCHAR(250),tag NVARCHAR(200),remark text,status integer default 0,rowTime timestamp default (datetime('now', 'localtime')))";
    final private static String[] mInsertSqlForNoteClass={"insert into NoteClass(className) values('默認分類[私有]');","insert into NoteClass(className) values('讀書筆記[私有]');","insert into NoteClass(className) values('電子資料[公開]');"};
    private DBHelper(Context context, CursorFactory factory) {
        super(context, mDbName, factory, mDbVersion);

    }

public static DBHelper GetInstance(Context context, SQLiteDatabase.CursorFactory factory)
{
    if(mInstance==null){
        mInstance = new DBHelper(context,factory);  
    }
    return mInstance;
}

@Override
public void onCreate(SQLiteDatabase db) {
    // 創建表
    db.execSQL(mCreateSqlForNoteClass); 
    db.execSQL(mCreateSqlForUserPhoto);
    //初始化數據
    for(int i=0;i<mInsertSqlForNoteClass.length;i++)
        db.execSQL(mInsertSqlForNoteClass[i]);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

private Cursor ExecSQLForCursor(String sql, String[] selectionArgs){
    SQLiteDatabase db =getWritableDatabase();
    Log.i("ExecSQLForCursor",sql);
    return db.rawQuery(sql, selectionArgs);
}
private void ExecSQL(String sql){
    try{
        SQLiteDatabase db =getWritableDatabase();
        ExecSQL(sql,db);
    }catch(Exception e){
        Log.e("ExecSQL Exception",e.getMessage());
                e.printStackTrace();
    }
}
private void ExecSQL(String sql,SQLiteDatabase db ){
try{
        db.execSQL(sql);    
        Log.i("ExecSQL",sql);
    }catch(Exception e){
        Log.e("ExecSQL Exception",e.getMessage());
            e.printStackTrace();
    }
}
//添加照片信息
public long InsertUserPhoto(String photoName,String title){
    SQLiteDatabase db =getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put("photoName", photoName);
    cv.put("title", title);
    return db.insert(mTUserPhoto, null, cv);
}
//查詢照片信息
public Cursor SearchPhoto(int row,String sort){
    Cursor cur = null;
    try{
        String ord = (sort==null|| sort.toLowerCase().startsWith("a"))?"asc":"desc";
        String sql = "select * from UserPhoto order by photoId "+ord;
        String[] args = {String.valueOf(row)};
        if(row>0){
            sql +=" limit ?";
        }else{
            args=null;
        }
        cur = ExecSQLForCursor(sql,args);           
    }catch (Exception e) {
        cur = null;
        Log.e("SearchPhoto Exception",e.getMessage());
        e.printStackTrace();
    }
    return cur;
}   
//修改照片信息
public int UpdateUserPhoto(int photoId,int classId,String title,String content, String tag){
    SQLiteDatabase db =getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put("classId", classId);
    cv.put("title", title);
    cv.put("content", content);
    cv.put("tag", tag);
    String[] args = {String.valueOf(photoId)};
    return db.update(mTUserPhoto, cv, "photoId=?",args);              
}
//刪除照片信息
public int DeleteUserPhoto(int photoId){
    SQLiteDatabase db =getWritableDatabase();
    String[] args = {String.valueOf(photoId)};
    return db.delete(mTUserPhoto, "photoId=?", args);
}

}</pre>主要用到的類：SQLiteOpenHelper、SQLiteDatabase及ContentValues