I am trying to filter my products based on the price range set by the user. For this am using range slider but am not getting any product in this range:- Code for range slider:-

SfRangeSlider(
            min: 0.0,
            max: 20000.0,
            showLabels: true,
            showTicks: true,
            enableTooltip: true,
            values: _values,
            activeColor: Themes.selectedColor,
            inactiveColor: const Color(0xffc0c0c0),
            tooltipTextFormatterCallback: (a, s)=>"₹ $s",
            onChanged: (SfRangeValues newValues) {
              products.removeWhere((element) => element.price!<_values.start&&element.price!>_values.end);
              if(products.length<8){
                getData();
              }
              setState(() {
                _values = newValues;
              });
            },
          ),

and my code to fetch the data:-

void getData()async
  {
    QuerySnapshot snapshot=await productReference.where('category',isEqualTo: widget.category).where("price",whereIn: [_values.start,_values.end]).limit(12).get();
    if(snapshot.docs.isNotEmpty){
      for (DocumentSnapshot doc in snapshot.docs) {
        products.add(ProductModel.fromDocument(doc));
      }
      lastDoc=snapshot.docs.last;
    }
    setState(() {
      loading=false;
      load=false;
    });
  }

But i am not able to receive any document. Even though product exists in the price range. For testing i choose 0 and 20,000 as default value to check.

P.S:- Do i need to create any index? If so then what values for it?

CodePudding user response：

whereIn checks for exact match with the values you give.

What you want to do is:

QuerySnapshot snapshot = await productReference
    .where('price', isLessThanOrEqualTo: _values.end)
    .where('price', isGreaterThanOrEqualTo: _values.start)
    .limit(12)
    .get();

For your question regarding indexes: If you need to create one, firestore will likely tell you and give you a ling to create it automatically so I would not worry about that.

Another note: I think your method of retrieving data will cause a lot of calls to the database. I would wait only the value does not change for 200ms for example before fetching and changing the data. Just a thought but do what you must ;)