public class Version
{
public byte Major { get; set; }
public byte Minor { get; set; }
public short Build { get; set; }
public int Revision { get; set; }
private long NumVersion
{
//get {}
//set {}
//Some logic that make Int64 number that represents this verion
}
}
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假设我希望能够编写类似的查询
Where<Product>(t=>t.Version > new Version(1,2,0,0))
在Product表中,我只存储Int64 NumVersion字段,因此Version属性被映射为组件,目前我查询它 Where<Product>(t=>t.Version.NumVersion > new Version(1,2,0,0).NumVersion)
在C#中,我可以1.重载比较运算符,2.使其隐式转换为:
public static implicit operator long(Version v)
{
return v.NumVersion;
}
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这将允许我比较Version对象,但是如何让NHibernate理解这一点并生成正确的SQL?