嗨,我只想在sql
中做到这一点SELECT ID,Name
FROM Countrys
UNION all
SELECT '00000000-0000-0000-0000-000000000000','All' Name
ORDER BY Id
在组合框上使用“ALL”选项
using (GezentiEntities GE = new GezentiEntities())
{
string[,] str = new string [1,2]{ {"00000000-0000-0000-0000-000000000000", "All"} };
var obj = str.Cast<object>().ToArray();
var countries = (from c in GE.Countrys select new { c.Id, c.Name })
.Concat
(from s in obj select s);
cmbNationality.DataSource = countries.ToList();
cmbNationality.ValueMember = "Id";
cmbNationality.DisplayMember = "Name";
}
它给了我这个错误:
无法创建“System.Object”类型的常量值。在此上下文中仅支持原始类型或枚举类型。
答案 0 :(得分:3)
只需将您的匿名类型查询放入列表中,然后使用列表的add方法附加匿名类型。
注意在add中选择和后续命名中的变量命名,以确保它们匹配。
var countries = (from c in GE.Countrys
select new {Id = c.Id,Name = c.Name}).ToList();
countries.Add(new {Id = "00000000-0000-0000-0000-000000000000", Name = "All"});