Capitulo 41 ➜ Métodos de consulta a la DB

Métodos de consulta a la Base de datos

package codea.app.pizzeria9.database;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

import java.util.ArrayList;
import java.util.List;

import codea.app.pizzeria9.modelo.Carrito;

public class DBManager {
    private DbHelper helper;
    private SQLiteDatabase database;
    private Context context;

    public DBManager(Context myContext){
        context = myContext;
    }

    public DBManager open() throws SQLException{
        helper = new DbHelper(context);
        database = helper.getWritableDatabase();
        return  this;
    }
    public void close(){
        helper.close();
    }

    // agregar un item al carrito de compra
    public void addItem(String nombre, double precio, int cantidad, String tamano, double importe, String foto, int producto_id){
        ContentValues contentValue = new ContentValues();
        contentValue.put(DbHelper.NOMBRE,nombre);
        contentValue.put(DbHelper.PRECIO,precio);
        contentValue.put(DbHelper.CANTIDAD,cantidad);
        contentValue.put(DbHelper.TAMANO,tamano);
        contentValue.put(DbHelper.IMPORTE,importe);
        contentValue.put(DbHelper.FOTO,foto);
        contentValue.put(DbHelper.PRODUCTO_ID,producto_id);
        database.insert(DbHelper.TABLE,null,contentValue);
    }

    // check del item
    public Cursor checkItem(String condicion) throws SQLException{
        String query = "SELECT * FROM "+DbHelper.TABLE+ " WHERE " + condicion;
        Cursor cursor = database.rawQuery(query,null);
        return cursor;
    }

    public void updateItem(String campo, String condicion) throws SQLException{
        String query = "UPDATE "+DbHelper.TABLE+ " SET "+campo+ " WHERE " + condicion;
        database.execSQL(query);
    }

    public void removeItem(int id){
        database.delete(DbHelper.TABLE,"_id="+id,null);
    }
    public void clearItems(){
        database.delete(DbHelper.TABLE,null,null);
    }


    public Cursor carritoAll(String condicion) throws SQLException{
        String query = " SELECT * FROM "+DbHelper.TABLE + " WHERE "+condicion;
        Cursor cursor = database.rawQuery(query,null);
        if(cursor!=null)
            cursor.moveToFirst();
        return cursor;
    }

    public double getSubTotal(String campo){
        double dato=0.00;
        String query= "SELECT SUM("+campo+") FROM " +DbHelper.TABLE;
        Cursor cursor = database.rawQuery(query,null);
        if(cursor.moveToFirst()){
            dato =cursor.getDouble(0);
        }
        cursor.close();
        return dato;
    }



}