合并两个查询结果

Question

I have following two Queries on Same Table and need to merge it.

 var Prod = this.UnitOfWork.myRepository.GetData();
 var PreProd = this.UnitOfWork.myRepository.GetData();

 var Merge = Prod.Union(PreProd);

But when i check results of Merge it doesn't show Union but shows following message

Message: This method supports the LINQ to Query Result Union not working Entities infrastructure and is not intended to be used directly from your code

How this can be accomplished.

Answer 1

You can use .AsEnumerable() to convert IQueryable to IEnumerable firstly.

 var Prod = this.UnitOfWork.myRepository.GetData().AsEnumerable();
 var PreProd = this.UnitOfWork.myRepository.GetData().AsEnumerable();

 var Merge = Prod.Union(PreProd);

Answer 2

LINQ to EF supported Union :

IQueryable<TSource> Union<TSource>(
this IQueryable<TSource> source1,
IEnumerable<TSource> source2
)

so try:

 var Prod = this.UnitOfWork.myRepository.GetData();
 var PreProd = this.UnitOfWork.myRepository.GetData();

 var Merge = Prod.Union(PreProd.AsEnumerable());