Question

我正在学习Android工作室，本周开始使用数据库。我想对这个应用程序有点帮助。很简单。用户输入字符串并按下第一个活动中的按钮。然后将此字符串发送到第二个活动，并将其与数据库中的值进行比较，并显示相似的值：

public class DrinkCategoryActivity extends ListActivity {
public static final String EXTRA_MESSAGE = "message";
private SQLiteDatabase db;
private Cursor cursor;
private Cursor newcursor;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Intent intent = getIntent();
    String messageText = intent.getStringExtra(EXTRA_MESSAGE);
    //setContentView(R.layout.activity_drink_category);
    ListView listDrinks = getListView();
    try{
        SQLiteOpenHelper starbucksDatabaseHelper = new StarbucksDatabaseHelper(this);
        db = starbucksDatabaseHelper.getReadableDatabase();
        /*
            SELECT _id, NAME FROM DRINKS;
         */
        cursor = db.query("DRINK",
                    new String[]{"_id", "NAME"},
                    null, null, null, null, null);
        newcursor = cursor.equals(messageText);
        CursorAdapter listAdapter = new SimpleCursorAdapter(this,
                android.R.layout.simple_list_item_1,
                cursor,
                new String[]{"NAME"},
                new int[]{android.R.id.text1},
                0);

        listDrinks.setAdapter(listAdapter);

    }catch (SQLiteException ex){
        Toast toast = Toast.makeText(this, "Database unavailable",
                Toast.LENGTH_LONG);
        toast.show();
    }

我一直在寻找网络，但我找不到一个好的解释。数据库

这是数据库中的饮料

public class StarbucksDatabaseHelper extends SQLiteOpenHelper{
    add a varaible for the db name
    private static final String DB_NAME = "starbucks";

    version of the database
    private static final int DB_VERSION = 1;

    StarbucksDatabaseHelper (Context context){
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE DRINK ("
                + "_id INTEGER PRIMARY KEY AUTOINCREMENT, "
                + "NAME TEXT, "
                + "DESCRIPTION TEXT, "
                + "IMAGE_RESOURCE_ID INTEGER);");
     insert data
        insertDrink(db, "Soy Latte", "Esspresso and steamed soy milk", R.drawable.latte);
        insertDrink(db, "Mocaccino", "Esspresso, hot milk, steamed milk foam, and cocoa", R.drawable.cappuccino);
        insertDrink(db, "American", "Drip coffee", R.drawable.filter);
    }

    private static void insertDrink (SQLiteDatabase db,
                                     String name,
                                     String description,
                                     int resourceId){
        ContentValues drinkValues = new ContentValues();
        drinkValues.put("NAME", name );
        drinkValues.put("DESCRIPTION", description);
        drinkValues.put("IMAGE_RESOURCE_ID", resourceId);


        db.insert("DRINK", null, drinkValues);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

Answer 1

如果您希望检索在开头，中间或结尾包含messageText的任何行，请尝试此查询 -

cursor = db.query("DRINK", new String[]{"_id", "NAME"}, "NAME like %?%", new String[]{messageText}, null, null, null);

将输入字符串与数据库中的字符串进行比较

1 个答案: