使用

IF EXISTS(SELECT * FROM @Words)

不是

IF @Words IS NOT NULL

表值参数将始终存在，并且不能像标量参数那样 NULL.

The table valued parameter will always be present and can't be NULL like a scalar parameter.

如果你调用 exec [dbo].[SearchByWord] 而不传递任何参数，结果是 @Words 将是空表.

If you call exec [dbo].[SearchByWord] without passing anything for the parameter the result is that @Words will be empty table.