我正在学习Android Studio,并在本周开始使用数据库。我想对这个应用程序有一点帮助。很简单。用户输入一个字符串并在第一个活动中按下一个按钮。此字符串,然后被发送到它与数据库中的值进行比较,并显示类似的那些第二个活动:将输入字符串与数据库中的字符串进行比较
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();
}
我一直在寻找所有网站上,但我不能找到一个很好的解释。 数据库
这是数据库中是饮料
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) {
}
为什么添加newcursor = cursor.equals(messageText);?另外,你的问题的答案取决于你想如何匹配字符串与你的数据库 - 完全相同或包含该字符串,从它开始,以它结束,.....? –
我忘了删除它。我会喜欢它是否可以通过世界检查世界,因为数据库中的字符串可以有更多的两个世界,而且我希望它显示所有类似于用户输入的字符串的字符串 – djant
您可以通过给出解释一个例子 ? –