合并2个LINQ列表时出错

Question

合并2个LINQ列表后，我遇到了问题。我收到以下错误：查询包含对在不同数据上下文中定义的项的引用。

这就是我构建最终2个LINQ列表的方式：

CAPDBDataContext CAdb = new CAPDBDataContext();
USPDBDataContext USdb = new USPDBDataContext();

var ExceptionList = Special_texts.Where(x => x.name.Equals("ExceptionList"))
                    .Select(x => x.special_text1)
                    .AsEnumerable()
                    .Select(x => x.Split(new[] { '#' }, StringSplitOptions.RemoveEmptyEntries))
                    .SelectMany(x => x)
                    .ToList();

var USquery = from uscomp in USdb.UScompanies
              join ussect in USdb.USsectors
              on uscomp.sector_code equals ussect.sector_code
              select new
              {
                  uscomp.company_name,
                  uscomp.primary_exchange,
                  ussect.description
              };

var CAtemp = from x in CAdb.companies
             where !ShefalisList.Contains(x.ticker)
             select x;

var CAquery = from temp in CAtemp
             join casect in CAdb.sectors
             on temp.sector_code equals casect.sector_code
             select new
             {                          
                 temp.company_name,
                 temp.primary_exchange,                             
                 casect.description
             };

 var mergedList = USquery.Union(CAquery).ToList();

我做错了什么？

Answer 1

请改为：

var mergedList = USquery.AsEnumerable().Union(CAquery).ToList()

如果不将结果存入内存，则无法Union查询不同的数据库。