Android SQLite最简单demo实现（增删查改）

package com.example.SQLiterTest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * 可以通过SQLiteOpenHelper的以下两个方法来或得SQLiteDatabase的对象：
 * getReadableDatabase() 创建或者打开一个查询数据库
 * getWritableDatabase() 创建或者打开一个可写数据库 
 */
public class DBHelper extends SQLiteOpenHelper {

    /**
     * 构造函数，必须实现
     * @param context 上下文路径
     * @param name 数据库名称
     * @param factory 可选游标工厂，通常为NULL
     * @param version 当前数据库版本号
     */

    private SQLiteDatabase mDataBase = null;
    private static final String USER_TABLE = "user";

    public DBHelper(Context context, String name, CursorFactory factory,
                    int version) {
        super(context, name, factory, version);
        mDataBase = this.getWritableDatabase();
    }


    //数据库第一次创建时会调用，一般在其中创建数据库表
    @Override
    public void onCreate(SQLiteDatabase db) {
        //使用execSQL()方法执行SQL语句，如果没有异常，这个方法没有返回值
        db.execSQL("create table user(id INTEGER PRIMARY KEY AUTOINCREMENT," +
                "name varchar(20), address TEXT)");
        Log.v("mytab","-->onCreate");
    }

    //当数据库需要修改的时候，Android系统会主动的调用这个方法。
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}

    //打开数据库时的回调函数，一般不会用
    @Override
    public void onOpen(SQLiteDatabase db) {
        super.onOpen(db);
        Log.v("mytab","-->onOpen");
    }

    @Override
    public synchronized void close() {
        super.close();
    }

}

package com.example.SQLiterTest;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;

public class MyActivity extends Activity {
    /**
     * Called when the activity is first created.
     */
    private SQLiteDatabase db;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


        // 获取处理SQLiteOpenHelper的子类的SQLite的实例，如果只读，可以采用getReadableDatabase()，
        // 这个例子我们奖通过SQLiteDatabase实例的操作，来进行对数据进行增删改查询，采用可写的方式。
        db = new DBHelper(getApplicationContext(),"mydb",null,1).getWritableDatabase();
        ContentValues cv = new ContentValues();
        cv.put("name", "JackLi");
        cv.put("address", "QingYuan");
        //插入
        db.insert("user",null,cv);
        Log.v("mytab","-->have insert");
        //更新
        ContentValues cv2 = new ContentValues();
        cv2.put("name","HaiXin");
        db.update("user",cv2,"name=?",new String[]{"JackLi"});
        Log.v("mytab","-->have updated");

        //查询
        String[] columns = {"name", "address"};
        Cursor cursor = db.query("user",columns,"name = ?", new String[] {"HaiXin"},null,null,null);
        while (cursor.moveToNext())
        {
            String myname = cursor.getString(cursor.getColumnIndex("name"));
            Log.v("mytab","---->"+myname);
        }

        //删除
        db.delete("user","name = ?",new String[]{"HaiXin"});
        Log.v("mytab","-->have delete");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        db.close();
    }
}

05-19 08:08:30.864    1802-1802/com.example.SQLiterTest V/mytab﹕ -->onOpen
05-19 08:08:30.872    1802-1802/com.example.SQLiterTest V/mytab﹕ -->have insert
05-19 08:08:30.888    1802-1802/com.example.SQLiterTest V/mytab﹕ -->have updated
05-19 08:08:30.888    1802-1802/com.example.SQLiterTest V/mytab﹕ ---->HaiXin
05-19 08:08:30.900    1802-1802/com.example.SQLiterTest V/mytab﹕ -->have delete