Ok I am having a look at it now, I will definitely need to apply similar logic in the future, so best I brush up now.

Feel free to update the...

holy crap!! Obi-Wan has taught you well!!

Thanks a million Jared I thought I wouldn't be able to solve this!

You are my new personal SQL Jesus lol or what ever flavor...

Hi Jared

Yes I have tried my @$$ off lol

Basically, I know you can compare a table to itself using a self join, and I know you can use the datediff...

Hi Jared

Ah, the reason for that is, I didn't want to give you irrelevant information.

I don't really care about the other columns. The only result I really want to see...

CREATE TABLE [dbo].[SAMPLE_TEST](

[ref] [nvarchar](60) NULL,

[SAMPLE_ID] [int] NOT NULL,

[SAMPLE_DATE] [datetime] NOT NULL,

[template_descr] [nvarchar](512) NULL,

[template_id] [int] NOT NULL,

[STARTING_DATE] [datetime] NOT NULL,

[FREQ_UNIT] [int] NULL,

[FREQ_VALUE] [int] NULL

) ON [PRIMARY]

GO

Hi Jared

Thanks for the quick reply.

I want to group by ref (description of the plant) , and by template_descr (there are actually different monitoring processes).

So each sample is basically taken...