在Linq-to-Entities查询表达式中使用元组或其他复杂类型

Question

所以我想在一个客户表中搜索所有客户,每个客户的名称,电子邮件地址或电话号码都匹配所有查询关键字.

...在代码中比在英语中更容易理解:

public IQueryable<Contact> SearchCustomers(string query)
{
    var ws = from w in query.Split()
                where !String.IsNullOrWhiteSpace(w)
                select w;

    var q =
        from c in Customers
        where ws.All(w =>
                c.FirstName == w
                || c.LastName == w
                || c.EmailAddress == w
                || c.HomePhone == PhoneNumber.Pack(w)
                || c.CellPhone == PhoneNumber.Pack(w))
        select c;

    return q;
}

但我不能调用PhoneNumber.Pack数据库,所以我需要制作w一个格式,既存储原始值w也包含Packed值,我必须在客户端执行此操作.问题是Linq不喜欢在表达式参数中使用元组或数组,并且它不支持String.IndexOf,因此我不能在一个中抛出两个字符串然后使用子字符串.

还有其他方法来解决这个问题吗？或者重新查询一下？

编辑:生成的SQL如下所示:

SELECT 
[Extent1].[ID] AS [ID], 
[Extent1].[FirstName] AS [FirstName], 
[Extent1].[LastName] AS [LastName], 
(etc)
FROM [dbo].[Contacts] AS [Extent1]
WHERE ( NOT EXISTS (SELECT 
    1 AS [C1]
    FROM  ( SELECT 1 AS X ) AS [SingleRowTable1]
    WHERE ( NOT ([Extent1].[FirstName] = N'rei' OR [Extent1].[LastName] = N'rei' OR [Extent1].[EmailAddress] = N'rei' OR [Extent1].[HomePhone] = N'rei' OR [Extent1].[CellPhone] = N'rei')) OR (CASE WHEN ([Extent1].[FirstName] = N'rei' OR [Extent1].[LastName] = N'rei' OR [Extent1].[EmailAddress] = N'rei' OR [Extent1].[HomePhone] = N'rei' OR [Extent1].[CellPhone] = N'rei') THEN cast(1 as bit) WHEN ( NOT ([Extent1].[FirstName] = N'rei' OR [Extent1].[LastName] = N'rei' OR [Extent1].[EmailAddress] = N'rei' OR [Extent1].[HomePhone] = N'rei' OR [Extent1].[CellPhone] = N'rei')) THEN cast(0 as bit) END IS NULL)
))

Answer 1

public IQueryable<Contact> SearchCustomers(string query)
{
    var ws = from w in query.Split()
                where !String.IsNullOrWhiteSpace(w)
                select new { Unpacked = w , Packed = PhoneNumber.Pack(w) };

    var q = Customers;
    foreach(var x in ws)
    {
        string ux = x.Unpacked;
        string px = x.Packed;
        q = q.Where(
               c=> 
                c.FirstName == ux
                || c.LastName == ux
                || c.EmailAddress == ux
                || c.HomePhone == px
                || c.CellPhone == px
            );
    }
    return q;
}

这将产生所需的结果，并且 foreach 内的临时变量将解决您的问题。