c# - LINQ/Projection - 包含用于过滤的所有通配符

Question

Contains("") 是否有等效的“*”？我正在使用一些通配符进行过滤，如果没有应用过滤器，那么我需要全部返回吗？

string[] filter = {1,2};  // This is dynamic could be filtered values or {} empty.

// This works for filtering by products (1,2)
db.Products.Where(x => filter.Contains(x.ProdId));

我真正需要实现的是这样的:

// If the filter is empty get all results...if there is a filter passed the filter values in for select
db.Products.Where(x => x.ProdId.Contains(filter.Length == 0 ? "*" : filter);

Answer 1

如有必要，您可以只添加位置:

var query = db.Products.AsQueryable();
if (filter.Any())
    query = query.Where(x => filter.Contains(x.ProdId));

// use query as needed