where do i use the "Block until Done" tool... with this scenario

[Raj_007]

Hi All, Thanks for your time,  i have this scenario where my workflow runs every day at 7AM (only 1 time)

I take few columns from my dataset and within the select tool i rename them to be like [AppID Prev] and write the data into an excel file

next day at 7AM when the workflow runs i want to read the data from the excel file so that i can do comparison like AppID which is in the dataset is current and the [AppID Prev] which is the excel file is previous --

I have to write the data into the excel file AFTER the calculations/comparions are done with the previous data coming from the excel file so

kind of confused on where i need to put the "Block Until Done"  - i took the input to get data  from the excel file then do some calcs 

The output file is to write the data into the excel file

[Qiu · Accepted solution]

@Raj_007 

For me, Block Until Done is typically used to re-use the output file.

For example, in Branch 1, I output some data to an Excel file, then use Branch Two I can read file in again to do something.

For your case, I feel its not a Block until Done application, rather a Union tool.

You can output your 'Today' data and in the input part, use a uniton to join today data and tomorrow data.

[Raj_007]

Hi Qiu,

So every day i have to write the data into the output excel file - before writing the data into the excel file i have to use whatever the data in the excel file

to compare against the current - say for ex: when we run the workflow the current AppID=101 - i have to test if AppID=AppID Prev - AppID Prev comes from the excel file. - Once the comparision is done i have to write the new data into the same file again

hopefully i am clear in explaining

[SeanAdams]

Hey @Raj_007 

It seems like you want to control the beginning of the second process (which is somewhat independant) based on completion of the first.

the most foolproof way do this is to wrap your sub-processes in batch macros - the great thing about batch macros is that you cannot proceed to the next step until the current step has finished - so you can control flow downstream.   It is a little bit of a learning journey though - so you may want to work through the training on Macros here: https://community.alteryx.com/t5/Interactive-Lessons/tkb-p/interactive-lessons/label-name/Macros

[Raj_007]

Thank you Qiu, and Sean, you guys are correct - i do not need the block until in my case. I read the data from the file and at the end of the work flow i write into the file - thanks for looking into this