Android SQLite数据库

SQLite数据库

SQLiteDatabase //管理操作数据库
    管理
    openDatabase //打开
    openOrCreateDatabase //打开或创建
    操作 增删改查
    execSQL //执行SQL语句
    insert //增
    update //改
    delete //删
    query //查
    rawQuery //sql语句查
    事物
    beginTransaction //开始
    endTransaction //结束
Cursor //查询结果
    move

SQLiteOpenHelper //管理数据库和版本更新
    onCreate //第一次创建数据库回调
    onUpgrade //数据库版本更新时回调
    getReadableDatabase //读的方式打开
    getWritableDatabase //写的方式打开
    close //关闭所有打开的SQLiteDatabase

Demo1 插入和查询数据

public class DBTest extends Activity {
    SQLiteDatabase db;

    Button bn = null;
    ListView listView;

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

        initTitle();
        initData();
        initView();

    }

    public void initTitle() {

    }

    public void initData() {

        db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString() + "/my.db3", null);

        try {
            db.execSQL("create table news_inf(_id integer" + " primary key autoincrement," + " news_title varchar(50),"
                    + " news_content varchar(255))");
        } catch (Exception e) {

            Log.i("TAG", "e---" + e);
        }
    }

    public void initView() {
        listView = (ListView) findViewById(R.id.show);
        bn = (Button) findViewById(R.id.ok);

        queryData();

        bn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View source) {
                String title = ((EditText) findViewById(R.id.title)).getText().toString();
                String content = ((EditText) findViewById(R.id.content)).getText().toString();

                try {
                    // 插入数据
                    insertData(db, title, content);

                    queryData();
                } catch (SQLiteException se) {

                }
            }
        });

    }

    // 插入数据
    private void insertData(SQLiteDatabase db, String title, String content) {
        // 执行插入语句
        db.execSQL("insert into news_inf values(null , ? , ?)", new String[] { title, content });
    }

    // 查询数据
    private void queryData() {
        Cursor cursor = db.rawQuery("select * from news_inf", null);
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(DBTest.this, R.layout.line, cursor, new String[] {
                "news_title", "news_content" }, new int[] { R.id.my_title, R.id.my_content },
                CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        listView.setAdapter(adapter);

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 退出程序时关闭SQLiteDatabase
        if (db != null && db.isOpen()) {
            db.close();
        }
    }

}

Demo2 单词本

public class Dict extends Activity implements View.OnClickListener{
    MyDatabaseHelper dbHelper;
    Button insert = null;
    Button search = null;

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

        initTitle();
        initData();
        initView();

    }

    public void initTitle() {

    }

    public void initData() {
        // 创建MyDatabaseHelper对象，指定数据库版本为1，此处使用相对路径即可，
        // 数据库文件自动会保存在程序的数据文件夹的databases目录下。
        dbHelper = new MyDatabaseHelper(this, "myDict.db3", 1);

    }

    public void initView() {
        insert = (Button) findViewById(R.id.insert);
        search = (Button) findViewById(R.id.search);
        insert.setOnClickListener(this);
        search.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.insert:// 插入
            String word = ((EditText) findViewById(R.id.word)).getText().toString();
            String detail = ((EditText) findViewById(R.id.detail)).getText().toString();

            insertData(dbHelper.getReadableDatabase(), word, detail);

            break;
        case R.id.search:// 搜索
            // 获取用户输入
            String key = ((EditText) findViewById(R.id.key)).getText().toString();
            // 执行查询
            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(Dict.this, ResultActivity.class);
            intent.putExtras(data);
            startActivity(intent);
            break;
        default:
            break;
        }
    }

    //插入
    private void insertData(SQLiteDatabase db, String word, String detail) {
        db.execSQL("insert into dict values(null , ? , ?)", new String[] { word, detail });
        Toast.makeText(Dict.this, "添加生词成功！", 8000).show();
    }

    //查询结果转集合
    protected ArrayList<Map<String, String>> converCursorToList(Cursor cursor) {
        ArrayList<Map<String, String>> result = new ArrayList<Map<String, String>>();
        // 遍历Cursor结果集
        while (cursor.moveToNext()) {
            // 将结果集中的数据存入ArrayList中
            Map<String, String> map = new HashMap<String, String>();
            // 取出查询记录中第2列、第3列的值
            map.put("word", cursor.getString(1));
            map.put("detail", cursor.getString(2));
            result.add(map);
        }
        return result;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 退出程序时关闭MyDatabaseHelper里的SQLiteDatabase
        if (dbHelper != null) {
            dbHelper.close();
        }
    }

}

public class MyDatabaseHelper extends SQLiteOpenHelper {
    final String CREATE_TABLE_SQL = "create table dict(_id integer primary " + "key autoincrement , word , detail)";

    public MyDatabaseHelper(Context context, String name, int version) {
        super(context, name, null, version);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // 第一次使用数据库时自动建表
        db.execSQL(CREATE_TABLE_SQL);
    }

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

public class ResultActivity extends Activity {

    List<Map<String, String>> list;

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

        initTitle();
        initData();
        initView();

    }

    public void initTitle() {

    }

    public void initData() {
        list = (List<Map<String, String>>) getIntent().getExtras().getSerializable("data");

    }

    public void initView() {
        ListView listView = (ListView) findViewById(R.id.show);
        SimpleAdapter adapter = new SimpleAdapter(ResultActivity.this, list, R.layout.line, new String[] { "word",
        "detail" }, new int[] { R.id.word, R.id.detail });
        listView.setAdapter(adapter);
    }

}

Code见 https://github.com/huanyi0723/SQLiteDemo/