我有这个在我的查询：

var results = (from urls in _context.Urls
               join documents in _context.Documents on urls.UrlId equals documents.DocumentId
               let words = (from words in _context.Words
                            join hits in _context.Hits on words.WordId equals hits.WordId
                            where hits.DocumentId == documents.DocumentId
                            select words.Text).AsEnumerable<string>()

                where urls.ResolvedPath.Contains(breakedQuery, KeywordParts.Url, part) ||
                      documents.Title.Contains(breakedQuery, KeywordParts.Title, part) ||
                      documents.Keywords.Contains(breakedQuery, KeywordParts.Keywords, part) ||
                      documents.Description.Contains(breakedQuery, KeywordParts.Description, part) ||
                      words.Contains(breakedQuery, KeywordParts.Content, part) ...

和包含扩展方法：

字符串

public static bool Contains(this string source, IEnumerable<string> values, KeywordParts valuePart, KeywordParts part)
    {
        if (!string.IsNullOrWhiteSpace(source))
            return source.Split(' ').AsEnumerable<string>().Contains(values, valuePart, part);
        return false;
    }

的可枚举（主要方法）

public static bool Contains(this IEnumerable<string> source, IEnumerable<string> values, KeywordParts valuePart, KeywordParts part)
    {
        if (source != null && source.Count() > 0 &&
            values != null && values.Count() > 0 &&
            (part == KeywordParts.Anywhere || valuePart == part))
        {
            foreach (var value in values)
            {
                var has = false;
                var none = (value.StartsWith("-"));
                string term = value.Replace("-", "");

                if (none)
                    has = source.Any(q => !q.Contains(value));
                else
                    has = source.Any(q => q.Contains(values));

                if (has)
                    return has;
            }
        }
        return false;
    }

和使用包含方法抛出异常的 NotSupportedException异常：方法布尔包含（字符串，IEnumerable`1 [字符串]，KeywordParts，KeywordParts）没有支持转换为SQL

and using Contains method throws exception NotSupportedException: Method 'Boolean Contains(String, IEnumerable`1[String], KeywordParts, KeywordParts)' has no supported translation to SQL.

其实我想，如果有在租约规定的条件之一，检查每个索引文件

actually i want to check each indexed document if have at lease one of specified conditions

推荐答案

您不能只写你自己的方法，并从查询的前pression称他们为 - 查询译者不知道该方法的意思做

You can't just write your own methods and call them from your query expression - the query translator has no idea what that method's meant to do.

您可能会迫使其中，子句将在.NET中获取的文件，也就是说，有可能......之后，虽然很明显，这意味着获取的所有从数据库中加入数据。请问这是否好吗？

You could force the where clause to be executed in .NET after fetching the documents and words, potentially... although obviously that means fetching all the joined data from the database. Would that be okay?

要做到这一点，你希望是这样的：

To do that, you'd want something like:

var tmpQuery = (from urls in _context.Urls
                join documents in _context.Documents 
                on urls.UrlId equals documents.DocumentId
                let words = (from words in _context.Words
                             join hits in _context.Hits 
                             on words.WordId equals hits.WordId
                             where hits.DocumentId == documents.DocumentId
                             select words.Text)
                select new { urls, documents, words };

var query = from r in tmpQuery.AsEnumerable()
            let urls = r.urls.ToList()
            let words = r.words.ToList()
            let documents = r.documents.ToList()
            where urls.ResolvedPath.Contains(breakedQuery, 
                                             KeywordParts.Url, part) ||
               documents.Title.Contains(breakedQuery,
                                        KeywordParts.Title, part) ||
               documents.Keywords.Contains(breakedQuery,
                                           KeywordParts.Keywords, part) || 
               documents.Description.Contains(breakedQuery, 
                                              KeywordParts.Description, part) ||
               words.Contains(breakedQuery, KeywordParts.Content, part)
            select new { urls, words, documents };