Trigger with Multiple Rows

I have written a trigger to log changes to a table and I of course didn't realize until after that this only works on one record at a time. Now I am trying to update it to allow for bulk updates and I cannot figure out how to do this.

CREATE TRIGGER [DT].[trg_LogChanges]
ON [DT].[NewDetails]
FOR UPDATE
AS 

DECLARE
    @TableName VARCHAR(100) ,
    @UpdatedDate smalldatetime ,
    @UpdatedBy uniqueidentifier

SELECT @TableName = 'DT.NewDetails'

IF EXISTS (SELECT 1 FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid)

    IF(SELECT ModifiedDate FROM INSERTED) Is Null
        SET @UpdatedDate = getdate()
    ELSE
        SET @UpdatedDate = (SELECT ModifiedDate FROM INSERTED)

    IF(SELECT ModifiedBy FROM INSERTED) Is Null
        SET @UpdatedBy = '11111111-1111-1111-1111-111111111111'
    ELSE
        SET @UpdatedBy = (SELECT ModifiedBy FROM INSERTED)


IF UPDATE (StatusID)
    BEGIN
        INSERT INTO DT.LogChanges
        (
            ChangeType, TableName, RecordGuid, FieldName
            , OldValue, NewValue, UpdatedBy, UpdatedDate
        )
        SELECT 
            'U', @TableName, d.Guid, 'StatusID'
            , d.StatusID, i.StatusID, @UpdatedBy, @UpdatedDate
        FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid
        WHERE 
            (d.StatusID IS NULL AND i.StatusID IS NOT NULL)
            OR (d.StatusID IS NOT NULL AND i.StatusID IS NULL)
            OR (d.StatusID <> i.StatusID)
    END

Can anyone offer up any help on how to fix this to work with multiple rows? I attempted the following by adding the SELECT 1 FROM INSERTED but I still get a subquery error message.

CREATE TRIGGER [DT].[trg_LogChanges]
   ON [DT].[NewDetails]
   FOR UPDATE
AS 

DECLARE
    @TableName VARCHAR(100) ,
    @UpdatedDate smalldatetime ,
    @UpdatedBy uniqueidentifier

SELECT @TableName = 'DT.NewDetails'

IF EXISTS (SELECT 1 FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid)

    IF(SELECT ModifiedDate FROM INSERTED) Is Null
        SET @UpdatedDate = getdate()
    ELSE
        SET @UpdatedDate = (SELECT ModifiedDate FROM INSERTED)

    IF(SELECT ModifiedBy FROM INSERTED) Is Null
        SET @UpdatedBy = '11111111-1111-1111-1111-111111111111'
    ELSE
        SET @UpdatedBy = (SELECT ModifiedBy FROM INSERTED)


IF UPDATE (StatusID)
    BEGIN
        IF EXISTS (SELECT 1 FROM INSERTED i
                    INNER JOIN DELETED d
                        on i.Guid = d.Guid
                    WHERE 
                        (d.StatusID IS NULL AND i.StatusID IS NOT NULL)
                        OR (d.StatusID IS NOT NULL AND i.StatusID IS NULL)
                        OR (d.StatusID <> i.StatusID))
        BEGIN
            INSERT INTO DT.LogChanges
            (
                ChangeType, TableName, RecordGuid, FieldName
                , OldValue, NewValue, UpdatedBy, UpdatedDate
            )
            SELECT 
                'U', @TableName, d.Guid, 'StatusID'
                , d.StatusID, i.StatusID, @UpdatedBy, @UpdatedDate
            FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid
            WHERE 
             开发者_运维知识库   (d.StatusID IS NULL AND i.StatusID IS NOT NULL)
                OR (d.StatusID IS NOT NULL AND i.StatusID IS NULL)
                OR (d.StatusID <> i.StatusID)
        END
    END

I have searched online but obviously I am still missing the correct way to do this. Any help would be greatly appreciated.

EDIT I spoke with the business owners of this process and they want to ignore the updates on multiple rows. Is there a way to add an IF around the entire trigger to ignore it if the records are more than 0?

Thanks

I believe your conditional checks can be minimized to CASE statements. It seems like you could minimize the entire trigger to

INSERT INTO DT.LogChanges (ChangeType, TableName, RecordGuid, FieldName, OldValue, NewValue, UpdatedBy, UpdatedDate)
  SELECT 'U', 'DT.NewDetails', d.Guid, 'StatusID', d.StatusID, i.StatusID,
CASE WHEN i.ModifiedBy IS NULL THEN GETDATE() ELSE i.ModifiedBy AS ModifiedBy, 
CASE WHEN i.ModifiedDate IS NULL THEN '11111111-1111-1111-1111-111111111111' ELSE i.ModifiedDate AS ModifiedDate
FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid
WHERE      (d.StatusID IS NULL AND i.StatusID IS NOT NULL)
    OR (d.StatusID IS NOT NULL AND i.StatusID IS NULL)
    OR (d.StatusID <> i.StatusID)

I didn't have time to make sure the syntax is perfect, but if you have some problems with it I can assist.

In response to your EDIT, that's done pretty easily with something like

IF (SELECT COUNT(*) FROM INSERTED i INNER JOIN DELETED d on i.Guid = d.Guid) = 1
BEGIN
PRINT 'Only one update record'
END