Sorry here is the link

https://onedrive.live.com/redir?resid=8952CE5DAEF23B26!114&authkey=!AG_hg0pt48Huqlg&ithint=file%2cxlsx

Hi everybody,

Here is an ambitious try as I am not developer.

SELECT Name_product, Purchase_Day

CASE

when cur.Name_product = prev.Name_product

AND cur.Purchase_Day <= '31/05/2014' then cur.Purchase_Day - prev.Purchase_Day as Durarion

when cur.Name_product <> prev.Name_product

AND cur.Purchase_Day >...

Hi pietlinden,

Thanks for your help,

As in example one customer can buy the same product many times, so the " Num_Customer " we will see it repeted several times and also...

Hi everybody,

Hi SSC-Enthusiastic

Thanks SSC-Enthusiastic for your proposal and thanks for all of you :

En réalité le nombre de lignes à présent ça remonte au plus d'un million d'enregistrements ce...

Hi,

I want just to rewrite my question in other way, so the exemple is the same but there is a macro may be someone can understand what I am asking.

The...

Hi,

sorry for my language, in fact I am not Sufficiently well in english especialy in the forum so I ask if I can write in french may be sommebody can...

I have data concerning sale of several products, columns are number of customer, date of purchase and name of product.

I need to calculate with SQL the average duration (number...