我已创建数据库以执行添加到购物车功能。 这是我的数据库助手类。
public class SQLiteHandler extends SQLiteOpenHelper {
private static final String TAG = SQLiteHandler.class.getSimpleName();
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "soulcluster";
// User table name
private static final String TABLE_USER = "user";
private static final String TABLE_PRODUCT = "product";
private static final String TABLE_ADD_TO_CART = "addtocart";
// User Table Columns names
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_PASSWORD = "password";
private static final String KEY_PRODUCT_ID = "id";
private static final String KEY_PRODUCT_IMAGE = "image";
private static final String KEY_PRODUCT_NAME = "productname";
private static final String KEY_PRODUCT_PRICE = "productprice";
private static final String KEY_PRODUCT_DESCRIPTION = "productdescription";
public SQLiteHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_USER_TABLE = "CREATE TABLE "
+ TABLE_USER + "("
+ KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_PASSWORD + " TEXT" + ")";
String CREATE_PRODUCT_TABLE = "CREATE TABLE "
+ TABLE_PRODUCT + "("
+ KEY_PRODUCT_ID + " TEXT PRIMARY KEY,"
+ KEY_EMAIL + " TEXT,"
+ KEY_PRODUCT_IMAGE + " BLOB NOT NULL,"
+ KEY_PRODUCT_NAME + " TEXT NOT NULL,"
+ KEY_PRODUCT_PRICE + " TEXT NOT NULL,"
+ KEY_PRODUCT_DESCRIPTION + " TEXT NOT NULL" + ")";
String CREATE_ADD_TO_CART_TABLE = "CREATE TABLE "
+ TABLE_ADD_TO_CART + "("
+ KEY_PRODUCT_ID + " TEXT PRIMARY KEY,"
+ KEY_PRODUCT_IMAGE + " BLOB NOT NULL,"
+ KEY_PRODUCT_NAME + " TEXT NOT NULL,"
+ KEY_PRODUCT_PRICE + " TEXT NOT NULL,"
+ KEY_PRODUCT_DESCRIPTION + " TEXT NOT NULL" + ")";
db.execSQL(CREATE_USER_TABLE);
db.execSQL(CREATE_PRODUCT_TABLE);
db.execSQL(CREATE_ADD_TO_CART_TABLE);
Log.d(TAG, "Database tables created" + CREATE_USER_TABLE + " " + CREATE_PRODUCT_TABLE + " " + CREATE_ADD_TO_CART_TABLE);
}
public void addToCart(String product_id, byte [] image, String productName, String productPrice, String productDescription){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_PRODUCT_ID, product_id);
contentValues.put(KEY_PRODUCT_IMAGE, image);
contentValues.put(KEY_PRODUCT_NAME, productName);
contentValues.put(KEY_PRODUCT_PRICE, productPrice);
contentValues.put(KEY_PRODUCT_DESCRIPTION, productDescription);
long id = db.insert(TABLE_ADD_TO_CART, null, contentValues);
db.close();
Log.d(TAG, "New product added into Add to cart " + product_id + " " + image + " " + productName + " " + productPrice + " " + productDescription + " " +id);
}
public void deleteAddToCartItem(String id){
try {
SQLiteDatabase db = this.getWritableDatabase();
String query = "delete from " + TABLE_ADD_TO_CART + " where id=\'" + id + "'";
Log.d("", "Id is here " + id);
db.execSQL(query);
db.close();
}catch (Exception e){
Log.d("", " Something is wrong");
}
}
public ArrayList<AddToCartItems> fetchProduct()
{
ArrayList<AddToCartItems> product = new ArrayList<>();
SQLiteDatabase db = this.getWritableDatabase();
String query = "select * from " + TABLE_ADD_TO_CART ;
Cursor cursor = db.rawQuery(query, null);
if(cursor.moveToFirst()){
do{
AddToCartItems addToCartItems = new AddToCartItems();
addToCartItems.setId(cursor.getString(0));
addToCartItems.setImageArray(cursor.getBlob(1));
addToCartItems.setName(cursor.getString(2));
addToCartItems.setPrice(cursor.getString(3));
addToCartItems.setDescription(cursor.getString(4));
product.add(addToCartItems);
Log.d("", "check -----" + cursor.getString(cursor.getColumnIndex("productname")) + " " + cursor.getString(cursor.getColumnIndex("id")));
cursor.moveToNext();
Log.d("", "Inside fetching method" + " " + cursor.getCount() + " " + product.size() );
System.out.print(cursor.getCount());
}while (cursor.moveToNext());
/* for (int a = 0; a < cursor.getCount(); a++){
}*/
}
Log.d("", "Checkimh product size " + product.size());
db.close();
return product;
}
我刚发布了必需的方法。 在我的适配器类中，单击添加到购物车存储桶，产品将添加到数据库中。
holder.add_to_cart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), items.getItem_Image());
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] bitmapdata = stream.toByteArray();
Date d = new Date();
SimpleDateFormat sm = new SimpleDateFormat("yyyymmddhhmmss");
String productID = sm.format(d);
db.addToCart(productID, bitmapdata, items.getItem_name(), items.getItem_price(), items.getDescription());
//AppController.getInstance().addToCartItemses(items.getItem_Image(), items.getItem_name(), items.getItem_price(), items.getDescription());
Log.d(""," ShopAdapter " + " " + bitmapdata + " " + productID + " " + items.getItem_Image() + " "+ items.getItem_name()+ " "+ items.getItem_price() +" " +items.getDescription());
}
});
这是方法。我使用了图像作为按钮，并在点击图像插入查询时触发。
这是下一个活动适配器类
中的删除方法
holder.delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
db.deleteAddToCartItem(addToCartItemses.get(position).getId());
addToCartItemses.remove(position);
notifyDataSetChanged();
}
});
为什么我的查询没有运行。
答案 0 :(得分：1)
您不必专门使用任何内容作为用户唯一ID，因为为每个登录用户分配了唯一ID ，您可以像这样检索它：
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user != null) {
// Name, email address, and profile photo Url
String name = user.getDisplayName();
String email = user.getEmail();
Uri photoUrl = user.getPhotoUrl();
// The user's ID, unique to the Firebase project. Do NOT use this value to
// authenticate with your backend server, if you have one. Use
// FirebaseUser.getToken() instead.
String uid = user.getUid();
}
此代码段可在官方firebase文档here
中找到如果此信息可以帮助您，请告诉我。