c# - LINQ to Entities 无法识别方法 'System.String ToString()' 方法并且此方法无法转换为存储表达式

Question

当我尝试运行以下代码时。

var result = from c in db.brand
             where c.title.contains("test")
             select c.title + "-" +c.brand;

List<string> lst = r.ToList();

它给出以下错误。

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

Answer 1

我建议以匿名类型获取标题和品牌，然后在进程中执行字符串连接:

var list = db.Brand.Where(c => c.Title.Contains("test"))
                   .Select(c => new { c.Title, c.Brand })
                   .AsEnumerable() // Rest of the query in-process
                   .Select(x => x.Title + " " + x.Brand)
                   .ToList();