how to fetch previous row's column values - [_THISROW-1]

[jaichith]

Hi friends,

  I am trying to get previous row's column value.  Can I use [_THISROW-1].[COLUMN NAME] ( It did not work as expected)?

What is the right expression to get immediate previous row value ?

I am using this expression in BOT - Wait condition and in a Virtual column

[lynchk21]

LOOKUP([_THISROW].[_RowNumber]-1, “table name", “_RowNumber”, “column name”)

[jaichith]

any other options - simpler expressions ? I came to know that lookup, select, filter are expensive functions and it needs more computation. 

Is there any other method available without using [RowNumber] as reference ?

[lynchk21]

Not that I am aware of 

[AleksiAlkio]

When you need to read from the whole table where that row is, you need to use some of those expressions and can't avoid it. One option is to use an additional normal column and read that column's value from the previous row. And because it's read with the initial value, it doesn't matter.

[jaichith]

Error : Error in expression '[_THISROW].[_RowNumber]' : Unable to find column '_RowNumber'

ISNOTBLANK(LOOKUP([_THISROW].[_RowNumber]-1,"TEST", "_RowNumber","SL NO")
)

[lynchk21]

Not sure why you are getting that error... Below is the same expression used in an app I have that doesn't produce that error. Is this in a virtual column? Or are you using it somewhere else?

[jaichith]

I was using it in Bot wait condition. 

https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/How-to-avoid-repeating-duplicates-when-multiple...

[jeni_lawren13]

HI,

LOOKUP([_THISROW].[_RowNumber]-1, “table name", “_RowNumber”, “column name”)

This code is providing the previous row's value

eg: row 5 : "Val1"

row 4: "Val0"

This code returns the value "Val0"

The actual requirement i have is to take the previous value of the current row's column.

Eg:

Column: Status

Step1: Status = Draft

Step2: Status = Move, here i need the value "save" to be stored in another column "Previous status". 

Is there any solution.?

[Steve]

https://support.google.com/appsheet/answer/11547057