CODEWITHSUNDEEP
c#asp.net-mvccontroller
karan
karan

Reputation: 482

How to get value from Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable in mvc controller

I know the title is somewhat complicate but let I clear the title by explaining the problem.

As per image I want to filter product name in search textbox. For ex: In search textbox if I enter the oil that in datatable whole data want to show which product name is oil.

For filter I used linq query, here is my code,

var dataList = (from x in query
    select new
    {
        PartName = _Db.Part.Where(z => z.Id == x.Select(p => p.PartId).FirstOrDefault()).Select(p => p.Name),
        ManufacturerName = _Db.Manufacture.Where(z => z.Id == x.Select(p => p.ManufacturerId).FirstOrDefault()).Select(p => p.name),
        CategoryName = _Db.Category.Where(z => z.Id == x.Select(p => p.CategoryId).FirstOrDefault()).Select(p => p.Name),
        Pcs = x.Sum(o =>o.Pcs) - 
        (from m in _Db.MaterialRecord
           join s in _Db.ServiceJob on m.ServiceJobId equals s.Id
           where m.pid == x.Select(p => p.PartId).FirstOrDefault()
           select m).Sum(z => z.Qty),
        Weight = _Db.Purchase.Where(p => p.Weight == x.Select(s => s.Weight).FirstOrDefault()).Select(a => a.Weight).FirstOrDefault(),      
        WeightType = x.Select(p => p.WeightTypeId).FirstOrDefault() > 0 ?((WeightType)x.Select(p => p.WeightTypeId).FirstOrDefault()).ToString() :"",
    }).ToList();

//Search    
if (!string.IsNullOrEmpty(searchValue))
    dataList = dataList.Where(m => m.CategoryName.Contains(searchValue.ToString().ToLower())).ToList();

//Returning Json Data
return Json(new { draw = draw, recordsFiltered = recordsTotal, recordsTotal = recordsTotal, data = data });

As per code I am getting whole data in datalist variable. Now, when I search any product in searchbox at that time the condition of search will true and after that the datalist value will be null[as shown by debug the code].

So, hence from that datatable shows null data.

For understanding that why this happening I add the tostring() in datalist query of category line i.e.

CategoryName = _Db.Category.Where(z => z.Id == x.Select(p => p.CategoryId).FirstOrDefault()).Select(p => p.Name).toString(),

After adding toString() in this line it shows this line Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable. But I want the result value of this line. For more clear lets see the another image

enter image description here

That oil result value I want in search condition line i.e.

dataList = dataList.Where(m => m.CategoryName.Contains(searchValue.ToString().ToLower())).ToList();

but right now in it is showing this line Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable in the place of result value.

Upvotes: 2

Views: 12602

Answers (1)

Tetsuya Yamamoto
Tetsuya Yamamoto

Reputation: 24957

First thing you should know is ToString() by its default implementation returns fully-qualified name of the object when applied to collection objects, in this case returns Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable<string> which is a reference type that doesn't override that method.

Let's evaluate this expression first:

CategoryName = _Db.Category.Where(z => z.Id == x.Select(p => p.CategoryId).FirstOrDefault())
                           .Select(p => p.Name),

Assumed that Category has DbSet<Category> type, the Select() extension method used in code above returns EntityQueryable<string> which contains result set collection from executed SQL statement provided by LINQ-to-Entities query. If you want to pull single string value from that collection, you must use one of the First(), Single(), FirstOrDefault() or SingleOrDefault() extension methods.

Hence, you should add extension method as mentioned above to return a string value instead of a collection:

var dataList = (from x in query
    select new {
        // other properties

        CategoryName = _Db.Category.Where(z => z.Id == x.Select(p => p.CategoryId).FirstOrDefault())
                               .Select(p => p.Name).SingleOrDefault(),

        // other properties
    }).ToList();

Then you can use Contains against a substring (searchValue) because CategoryName has string type:

dataList = dataList.Where(m => m.CategoryName.Contains(searchValue.ToString().ToLower())).ToList();

Reference:

Entity Framework/Core and LINQ to Entities Query Methods (Operators)

Upvotes: 2

Related Questions