在将某一约束应用于泛型类型参数时，必须存在从具体参数到该约束类型的隐式标识或引用转换。
When a constraint is applied to a generic type parameter, an implicit identity or reference conversion must exist from the concrete argument to the type of the constraint.
这些支持通过行标识符(RID_BIT或RID)内置函数、ROWCHANGETOKEN表达式、基于时间的更新检测和隐式隐藏的列实现。
This support is added using the row identifier (RID_BIT or RID) built-in function, the row CHANGE TOKEN expression, the time-based update detection, and implicitly hidden columns.
如果您拥有类，则可移除约束或执行某一操作以启用隐式引用或标识转换。
If you own the class, you can remove the constraint or else do something to enable an implicit reference or identity conversion.
如果您拥有类，则可移除约束或执行某一操作以启用隐式引用或标识转换。
If you own the class, you can remove the constraint or else do something to enable an implicit reference or identity conversion.
应用推荐