如何从数据库向按钮添加值

Question

我想创建一个pos，我想向来自Sqlite数据库的按钮插入数据。这样，当我单击按钮时，数据名称和价格就会显示出来。

public class DatabaseHelper  extends SQLiteOpenHelper {

    public static final String DATABASE_NAME = "MenuDB";

    //Menu's Tables NAME
    public static final String Table_Product = "Product";

    //Menu's column
    private static final String COL_1 = "ID";
    private static final String COL_2 = "NAME";
    private static final String COL_3 = "PRICE";
    private static final String COL_4 = "TYPE";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String CreateTableMenu = "CREATE TABLE IF NOT EXISTS " + Table_Product + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " +
                " NAME TEXT, PRICE TEXT, TYPE TEXT)";
        db.execSQL(CreateTableMenu);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + Table_Product);
    }

Answer 1

首先，您应该在DatabaseHelper上创建一个接受插入数据的方法，如下所示。

public boolean insertData(String name, String price, String type) { /required parameters
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2, name);
        contentValues.put(COL_3, price);
        contentValues.put(COL_4, type);
        db.insert(Table_Product, null, contentValues);

        return true;
    }

然后在要添加数据时在活动中这样称呼它。

new DatabaseHelper(MainActivity.this).insertData(name, price, type); //supply the parameters.