修改表中數據的兩種方法（update改）

1.通過點擊按鈕來執行修改表中數據。（數據庫和表的創建不在詳細介紹，請自動閱讀數據庫和表的創建）

第一種方法：直接使用SQL來操作數據庫，調用execSQL(sql)語句

public class MainActivity extends AppCompatActivity {
    private Button mPudateButton;
    private MySqliteHelper mMySqliteHelper;
    private SQLiteDatabase db;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMySqliteHelper = DbManger.getIntance(MainActivity.this);
        mPudateButton = (Button) findViewById(R.id.update_btn);
        //點擊按鈕插入數據
        mPudateButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                db = mMySqliteHelper.getWritableDatabase();
                String sql = "update "+Constant.TABLE_NAME+
                        " set "+Constant.NAME+ " = '小明' where "+Constant.ID+" = '3'";
                db.execSQL(sql);
                db.close();
            }
        });
    }
}

第二種方法：使用android API封裝好的修改數據的操作

public class MainActivity extends AppCompatActivity {
    private Button mUpdateButton;
    private MySqliteHelper mMySqliteHelper;
    private SQLiteDatabase db;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMySqliteHelper = DbManger.getIntance(MainActivity.this);
        mUpdateButton = (Button) findViewById(R.id.update_btn);
        //點擊按鈕插入數據
        mUpdateButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                db = mMySqliteHelper.getWritableDatabase();
                ContentValues values = new ContentValues();
                values.put(Constant.NAME,"小七");
                db.update(Constant.TABLE_NAME,values,""+Constant.ID+" = ?",new String[]{"1"});
                db.close();
            }
        });
    }
}