如何在LinqToSQL查询中使用我的枚举? [英] How do I use my enumeration in a LinqToSQL query?
问题描述
创建表MyTable(
...
状态tinyint不为空,
...
)
在我的C#类中我有
public enum TStatus:byte {
Pending = 1
Active = 2,
Inactive = 3,
}
public TStatus MyStatus {
get {return(TStatus)Status; }
set {Status =(byte)value; }
}
现在我想编写一个使用 MyStatus
属性 MyTable
例如
var q = MyDataContext.GetTable< MyTable>()。其中(t => t.MyStatus == TStatus.Active);
但当然,Linq不知道如何解释 MyStatus
作为SQL。
为了使其在LinqToSQL中工作,我需要执行哪些 MyStatus
?
查看此链接:
http://dotnet.org.za/hiltong/archive/2008/08/06/using-enums-with -linq-to-sql.aspx
由于链接死亡 - 至少对我来说,这个死了 - 这里是重要的部分:
默认情况下,将列添加到实体中时,Type将作为int(System.Int32)出现,但可以将其更改为完全限定类型的枚举(在我的情况下,ConsoleApplication1.CustomerType)。但是,为了完全找到它,你必须添加全局标识符,如下所示:global :: ConsoleApplication1.CustomerType,所以键入那个(但是等同于你的命名空间)到文本框中
I have a field in my database table that use to store an enumeration value, e.g.:
create table MyTable (
...
Status tinyint not null,
...
)
and in my C# class I have
public enum TStatus : byte {
Pending = 1
Active = 2,
Inactive = 3,
}
public TStatus MyStatus {
get { return (TStatus)Status; }
set { Status = (byte)value; }
}
now I want to write a Linq query that uses the MyStatus
property of MyTable
e.g.
var q = MyDataContext.GetTable<MyTable>().Where(t => t.MyStatus == TStatus.Active);
but of course, Linq doesn't know how to interpret MyStatus
as SQL.
What do I need to do to MyStatus
in order for it to work in LinqToSQL?
Check out this link:
http://dotnet.org.za/hiltong/archive/2008/08/06/using-enums-with-linq-to-sql.aspx
As links die - and at least for me this one did die - here is the important part:
[When adding the column to the entity] by default, the Type will come up as an "int (System.Int32)", but you can change it to the fully-qualified type of the enum (in my case, ConsoleApplication1.CustomerType). BUT, in order to locate it fully, you have to add the global identifier, as follows: global::ConsoleApplication1.CustomerType , so type that as is (but the equivalent for your namespace) into the textbox
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