diary start date and end date

Hello everyone

I have these data in a table:

And I want to change this structure like that:

Any idea how I do that?

Than you!

Hi @gabrielfs2 ,

To give a summary of my understanding of what you are trying to do…

You have for each “COD” value a START DATE and an END DATE (one per row)

You wish to generate a row for each DATE represented between START DATE and END DATE (inclusive) with the NEW DATE column representing each date within that period.

There may be more succinct ways to achieve this, which others me suggest, but to get you started here is one approach:

I have added comments to the nodes, so I hope it is reasonably explanatory. I suggest you review what each is doing, but if you have any questions then obviously come back with them.



Here is the demo workflow
Fill in dates between.knwf (56.0 KB)



Taking @takbb as benchmark and introducing another way of solving it.

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thanks everyone for the help so far

However, in my base I identified COD with several start date and end date, and the flow did not work, could you help me?


In the solution I have provided , All it takes is to increase the granularity by sending to the group loop
the start date and end date.
as bellow :
testing here it worked fine


PS. The group loop will do the operation ahead as many times as the unique combination of the data chosen

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Hi @gabrielfs2 , this is a good example of how knowing your data is crucial to describing the problem, and resolving. Without seeing your data we can only guess at the problem and the solutions provided will of course reflect those guesses.

On the face of it though, the new problem you have outlined is not insurmountable.

What you are looking for in database terms is a unique or “primary” key for the rows. The solution I provided is reasonably generic and involves the “rank” node grouping by one or more columns, and fortunately this can therefore be easily adapted to the new scenario.

Your initial data sample suggested that the primary key for your problem would be COD. Therefore the “rank” node in my uploaded workflow used “COD” as the grouping column.

If you have now determined that the combination of COD and START DATE together form the “primary key”, then change the RANK node so that it groups by COD and START DATE

With some different sample data as shown here, this would then handle those groupings

Of course, I can only once-again second-guess whether this will work for you with all of your data, and I’m going to now make the assumption that it is NOT unique on COD + START DATE.
It is quite possible that it IS unique on COD+START DATE+END DATE in which case I could use all three as the grouping in the Rank node, but I’ll show you what to do if it isn’t.

i.e. what do you do when you discover that no combination of columns makes your data unique. Well in that case you might want to question why you have duplicate rows, and possibly remove them, but let’s say for the sake of argument this scenario is valid. If you haven’t got a “unique key”, then you need to MAKE one! Placing a unique key on every row is actually easy. Just use an additional Counter Generation node prior to the One-Row-to-Many node. (and for good measure maybe rename the counter column as “PrimaryKey”). You can then group by just this PrimaryKey in the Rank node.

Then even if your initial data is not unique by any combination, this flow will still work.


I’ve left the new “PrimaryKey” column in to demonstrate the point. You’d probably want to add that into the column filter at the end to tidy things up.

Fill in dates between- primarykey.knwf (59.0 KB)

[Edit - you can see from the two responses, both from me and @Adrix, the solution in both cases is the same: change the “grouping” so that it groups by something that uniquely identifies the row of data ]

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