EF Core 2.2 LINQ query not working in EF Core 3.0

Question

Below code works fine at EF Core 2.2 bu not working on EF core 3.0

 var items = (from asset in Context.Assets               join assetCategory in Context.AssetCategories on asset.CategoryId equals assetCategory.Id               group assetCategory by assetCategory.Id into assetCategories               select new AssetCategorySummary               {                   CategoryId = assetCategories.Key,                   CategoryName = assetCategories.Select(p => p.CategoryName).FirstOrDefault(),                   TotalAsset = assetCategories.Count()               }).ToListAsync(); 

the error I am getting:

Processing of the LINQ expression 'AsQueryable(Select<AssetCategory, string>( source: NavigationTreeExpression Value: default(IGrouping<Guid, AssetCategory>) Expression: (Unhandled parameter: e), selector: (p) => p.CategoryName))' by 'NavigationExpandingExpressionVisitor' failed. This may indicate either a bug or a limitation in EF Core. See https://go.microsoft.com/fwlink/?linkid=2101433 for more detailed information.

need help please

Answer 1

This is due to one of the breaking changes in EF Core 3.0 and that is: LINQ queries are no longer evaluated on the client

So write the query in such way that EF Core can convert the expression into T-SQL or fetch the data into memory and then make your query.