Android 操作数据库的一个实例

核心提示：package com.Dictionary;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import android.app.Activity;import android.app.AlertDialog

package com.Dictionary;

import java.io.File;

import java.io.FileOutputStream;

import java.io.InputStream;

import android.app.Activity;

import android.app.AlertDialog;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import android.os.Bundle;

import android.text.Editable;

import android.text.TextWatcher;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.AutoCompleteTextView;

import android.widget.Button;

public class Dictionary extends Activity implements OnClickListener, TextWatcher{

private final String DATABASE_PATH = android.os.Environment

.getExternalStorageDirectory().getAbsolutePath();

//+ "/dictionary";

private final String DATABASE_FILENAME = "dictionary.db";

SQLiteDatabase database;

Button btnSelectWord;

AutoCompleteTextView actvWord;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

// 打开数据库，database是在Main类中定义的一个SQLiteDatabase类型的变量

database = openDatabase();

// 下面的代码装载了相关组件，并设置了相应的事件

btnSelectWord = (Button) findViewById(R.id.btnSelectWord);

actvWord = (AutoCompleteTextView) findViewById(R.id.actvWord);

btnSelectWord.setOnClickListener(this);

actvWord.addTextChangedListener(this);

}

public void onClick(View view)

{

// 查找单词的SQL语句

String sql = "select chinese from t_words where english=?";

Cursor cursor = database.rawQuery(sql, new String[]

{ actvWord.getText().toString() });