c# - 如何在 linq 表达式中格式化字符串？

Question

给定以下代码

IQueryable<string> customers = 
    from Customers in db.Customers
    where Customers.CstCompanyName.Contains(prefixText) && Customers.CstInactive == false
    select Customers.CstCompanyName + " (Phone: " + Convert.ToInt64(Customers.CstPhone).ToString("###-###-#### ####") + ")";

这是对我的 Entity Framework 的调用。我正在从数据库中返回一个电话号码。我正在尝试将其格式化为给定的格式字符串。不幸的是，当我运行它时，我收到以下错误:

LINQ to Entities does not recognize the method 'System.String ToString(System.String)' method, and this method cannot be translated into a store expression.

所以我的问题是如何将此数据库对象作为格式化字符串返回？

谢谢!

Answer 1

我会在数据库中执行查询，但在本地格式化:

var customers = db.Customers
                  .Where(c => c.CstCompanyName.Contains(prefixText))
                  .Select(c => new { c.CstCompanyName, c.CstPhone })
                  .AsEnumerable() // Switch to in-process
                  .Select(c => c.CstCompanyName + 
                               " (Phone: " +            
                               Convert.ToInt64(Customers.CstPhone)
                                      .ToString("###-###-#### ####") + ")");