In the image below, the total number of times which business is viewed each day is kept. What I want to do is to find the total number of views belonging to the same id number. For example, I want to find the total view value of records whose businessId is 400.

Database Table Image

CodePudding user response：

This will do the work, you may need to adapt some stuff indeed :

var totalViewsByBusinessId = records
    .GroupBy(r => r.businessId)
    .Select(g => new
    {
        BusinessId = g.Key,
        TotalViews = g.Sum(r => r.views)
    });

int businessId = 400;
var totalViews = totalViewsByBusinessId
    .FirstOrDefault(g => g.BusinessId == businessId)?.TotalViews ?? 0;

With that, you will get the total amount of views for each business. Then you will just need to use a where to see the total views of the wanted business.