SQL：嵌套查询没有适当的键

Question

In LINQ, I am trying to inner join custom function written for full-text search and an Iqueryable result.

However, I get the following error when I try to to_ret.select(--something--).ToList()

Nested query does not have appropriate key

LINQ Code:

  var sql_query = db.search(st);
  var to_ret = from ts in sql_query
               from t in table
               where t.Id == ts.Value select t;

  to_ret = to_ret.Include(x => x.table1)
                .Include(x=> x.table2.Select(y=> y.table2Col));

  to_ret.select(-something-).toList();

SQL Code:

create function [dbo].[search]
      (@keywords nvarchar(4000))
returns table
as
  return (
  select [key] from containstable(tb,(Name,Description),@keywords)
)

Code that works in place of above LINQ Code :

var ids = (from t in table join ts in db.search(st) on t.Id equals ts.Value select t.Id).ToList();

to_ret = to_ret.Where(x => ids.Contains(x.Id));

However, the code that works isn't efficient enough as it eagerly loads all the ids for comparison

Answer 1

Do not join the table using LINQ, it is not effective.

You need to include all the joined functions into [dbo].[search] table valued function (like a view). Then do just call the [dbo].[search] from EF and filter it.

I have mentioned joined Fulltext table valued function here.

Note that fulltext and filtering together in one query could take time, because it is not easy job for query optimizer. Query optimizer selects to perform first fulltext on entire table(s) and then filtering or the opposite way.