Android系统集成了一个轻量级数据库：sqlite。sqlite 只是一个嵌入式的数据库引擎，适用于资源有限的设备上。

sqlite支持大部分sql语法，允许开发者使用sql语句操作数据库的数据，但sqlite不需要安装和启动服务器进程，sqlite数据库只是一个文件。

sqliteDatabase类，用来操作数据库。它里面的静态方法提供了数据库的构造，当然使用sqliteOpenHelper 会更好，下面会介绍。

数据库的构造，静态方法

public static sqliteDatabase openDatabase(String path,CursorFactory factory,int flags);
public static sqliteDatabase openDatabase(String path,int flags,DatabaseErrorHandler errorHandler);

public static sqliteDatabase openOrCreateDatabase(File file,CursorFactory factory) ;
public static sqliteDatabase openOrCreateDatabase(String path,CursorFactory factory);

通过名字也能看出来，openOrCreateDatabase 当不存在时创建该数据库

数据库的操作，（增删改查）

void execsql(String sql,Object[] bindArgs); //执行带占位符的sql语句
void execsql(String sql);
Cursor rawQuery(String sql,String[] selectionArgs);

public long insert(String table,String nullColumnHack,ContentValues values);
public int update(String table,ContentValues values,String whereClause,String[] whereArgs)
public Cursor query(boolean distinct,String table,String[] columns,String selection,String[] selectionArgs,String groupBy,String having,String orderBy,String limit);
public int delete(String table,String[] whereArgs);

sqliteOpenHelper是android提供的一个管理数据库的工具类。一般使用它的子类，来管理数据库。

属于抽象类继承他需要实现void onCreate(sqliteDatabase db) 和void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion)方法，onCreate会在当用户获取数据库，不存在时，系统回调，用户不用管。onUpgrade 在数据库更新时回调
通过getReadableData(),getWritableDatabase()来获取sqliteDatabase对象，其中getReadableData 只能读操作，getWritableDatabase 读写操作。

实例，实现简单的类似单词本的查询添加功能：

MainActivity.java

package com.hipad.wordbook;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.sqliteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

	MyDatabaseHelper dbHelper;
	Button insert = null;
	Button search = null;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		dbHelper = new MyDatabaseHelper(this,"myDict.db3",null,1);
		insert = (Button)findViewById(R.id.main_button1);
		search = (Button)findViewById(R.id.main_button2);
		insert.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				String word = ((EditText)findViewById(R.id.edit1)).getText().toString();
				String detail = ((EditText)findViewById(R.id.edit2)).getText().toString();
				insertData(dbHelper.getReadableDatabase(),word,detail);
				Toast.makeText(MainActivity.this,"Add Success!",Toast.LENGTH_LONG).show();
			}
		});
		
		search.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				String key = ((EditText)findViewById(R.id.edit1)).getText().toString();
				Cursor cursor = dbHelper.getReadableDatabase().rawQuery(
						"select * from dict where word like ? or detail like ?",new String[]{"%"+ key +"%","%"+ key +"%"});
				Bundle data = new Bundle();
				data.putSerializable("data",converCursorToList(cursor));
				Intent intent = new Intent(MainActivity.this,ResultActivity.class);
				intent.putExtras(data);
				startActivity(intent);
			}
		});
	}
	
	protected ArrayList<Map<String,String>> converCursorToList(Cursor cursor){
		ArrayList<Map<String,String>> result = new ArrayList<Map<String,String>>();
		while(cursor.moveToNext()){
			Map<String,String> map = new HashMap<String,String>();
			map.put("word",cursor.getString(1));
			map.put("detail",cursor.getString(2));
			result.add(map);
		}
		return result;
	}
	private void insertData(sqliteDatabase db,String word,String detail){
		db.execsql("insert into dict values(null,?,?)",new String[]{word,detail});
	}
	
	@Override
	public void onDestroy(){
		super.onDestroy();
		if(dbHelper != null){
			dbHelper.close();
		}
	}

}

package com.hipad.wordbook;

import android.content.Context;
import android.database.sqlite.sqliteDatabase;
import android.database.sqlite.sqliteDatabase.CursorFactory;
import android.database.sqlite.sqliteOpenHelper;

public class MyDatabaseHelper extends sqliteOpenHelper {

	final String CREATE_TABLE_sql = "create table dict(_id integer primary "+
	"key autoincrement,detail)";
	public MyDatabaseHelper(Context context,String name,int version) {
		super(context,name,factory,version);
	}

	@Override
	public void onCreate(sqliteDatabase db) {
		db.execsql(CREATE_TABLE_sql);
	}

	@Override
	public void onUpgrade(sqliteDatabase db,int newVersion) {
		System.out.print("----------------------onUpdate Called--------------"
				+oldVersion + "----->"+newVersion);
		
	}

}

ResultActivity.java

package com.hipad.wordbook;

import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class ResultActivity extends Activity{

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.sec_activity);
		ListView listeView = (ListView)findViewById(R.id.listView);
		Intent intent = getIntent();
		Bundle data = intent.getExtras();
		List<Map<String,String>> list = (List<Map<String,String>>)data.getSerializable("data");
		SimpleAdapter adapter = new SimpleAdapter(ResultActivity.this,list,R.layout.simple_line,new String[]{"word","detail"},new int[]{R.id.simple_text1,R.id.simple_text2}
		);
		listeView.setAdapter(adapter);
	}

}

布局文件比较简单，这里就省略了。总之，使用sqlite，要属性sql语句，使用函数参数比较麻烦，大部分人应该不会使用。