Android：資料存放區之SQLite

標籤：

Android在運行時整合了SQLite ， 所以每個Android應用程式都可以使用SQLite資料庫。

我們通過SQLiteDatabase這個類的對象操作SQLite資料庫，而且不需要身分識別驗證。

資料庫存放的位置：data/data/<專案檔夾>/databases/，查看資料庫>>

執行個體：

public class MainActivity extends Activity {    private Button createDatabase, createTable, selectData, insertData,            updateData, deleteDaata;    private MySQLiteOpenHelper helper;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.demo);        // 初始化按鈕        createDatabase = (Button) findViewById(R.id.createDatabase);        createTable = (Button) findViewById(R.id.createTable);        selectData = (Button) findViewById(R.id.selectData);        insertData = (Button) findViewById(R.id.insertData);        updateData = (Button) findViewById(R.id.updateData);        deleteDaata = (Button) findViewById(R.id.deleteDaata);                        helper = new MySQLiteOpenHelper(MainActivity.this, "mydb.db",                null, 1);                /*         * 建立資料庫         */        createDatabase.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase = helper.getWritableDatabase();                Toast.makeText(MainActivity.this, "資料庫建立成功", 1000).show();            }        });        /*         * 建立表         */        createTable.setOnClickListener(new OnClickListener() {            public void onClick(View arg0) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase = helper.getWritableDatabase();                // 建立表                sqlitedatabase                        .execSQL("create table student(id INTEGER PRIMARY KEY autoincrement,name text)");                Toast.makeText(MainActivity.this, "表建立成功", 1000).show();            }        });        /*         * 插入資料         */        insertData.setOnClickListener(new OnClickListener() {            public void onClick(View v) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase = helper.getWritableDatabase();                sqlitedatabase                        .execSQL("insert into student(name) values (‘tinyphp‘)");                Toast.makeText(MainActivity.this, "插入資料成功", 1000).show();            }        });        /*         * 更新資料         */        updateData.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase = helper.getWritableDatabase();                sqlitedatabase                        .execSQL("update student set name=‘monkey‘ where id=‘1‘");                Toast.makeText(MainActivity.this, "資料更新成功", 1000).show();            }        });        /*         * 查詢資料         */        selectData.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase = helper.getReadableDatabase();                                //參數：表名、查詢的列、查詢條件、查詢參數、查詢結果分組、分組結果限制、排序                Cursor cursor = sqlitedatabase.query("student", new String[] {                        "id", "name" }, "id=?", new String[] { "1" }, null,                        null, null);                String name=null;                while(cursor.moveToNext()){                    name =cursor.getString(cursor.getColumnIndex("name"));                                    }                Toast.makeText(MainActivity.this, "查詢結果name為："+name, 1000).show();            }        });                /*         * 刪除資料         * */                        deleteDaata.setOnClickListener(new OnClickListener() {                        @Override            public void onClick(View v) {                // TODO Auto-generated method stub                SQLiteDatabase sqlitedatabase =helper.getWritableDatabase();                sqlitedatabase.delete("student", "id=?", new String[]{"1"});                Toast.makeText(MainActivity.this, "資料刪除成功", 1000).show();            }        });            }}

 使用getWritableDatabase或getReadableDatabase的時候，資料庫才會連結，通過execSQL執行SQL語句。

執行個體下載>>>>>>>>

Android：資料存放區之SQLite