+1 expression help

[NCD]

How do I write;

if a related grandchild record has been added +1

[Suvrutt_Gurjar]

May we know where do you want to write this? Meaning which table ( grand parent , same table?) and which column - real VC etc.

Could you elaborate a bit in more detail?

[NCD]

This expression is going to be written in my Action;

Type: set the values of some columns in this row

Inside of, Only if this condition is true

Which is going to be attached it to a Form's Event Action to trigger when the save button is clicked.

But I DO NOT want it to +1 every time the "save" button is clicked,but only when a new grandchild's record has been added and the "save" button is clicked.

So far I've;

1) created an action set the values of some columns in this row on Grandparent table.

2) created an action execute an action on a set of rows on my Parent table (so I can put it inside my Event Action)

3) The column I want to set is just a real column, type number, named [number]

[Suvrutt_Gurjar]

Thank you, could you add why you cannot use action in step 1 only as an event action?

Is the form on grand parent table? 

[NCD]

Like this;

[Suvrutt_Gurjar · Accepted solution]

I think you expression in the action that sets the values of column number in the grandparent table could be something like 

COUNT(SELECT(Grand Child Table [Grand Child table Key column], IN([Key column of Parent Table],[Related Parents column in the Grandparent Table] )))

Edit: This action can invoke on each save of the parent form but will change the count only based on number of grand child records. So if there is no addition to the grand child records, the action will simply write the same number again in the field. So you need not have any condition to invoke the action on the parent table.

[NCD]

It gives me a 0...

1)　Created an Action: Count number

  　For a record of this table: Grandparent

  　Do this: set the values of some columns in this row

  　Set these columns: number

  　COUNT(
  　SELECT(
  　Grandchild [id],
  　IN([id],[Related Parents] )
  　)
  　)

2) Created an Action:

  　For a record of this table: Parent

  　Do this: execute an action on a set of rows

  　Referenced Table: Grandparent

  　Referenced Rows: LIST(Grandparent_id)

  　Referenced Action: Count number

3) Put it in Event Actions of Form

[NCD]

I think I made it work by;

COUNT(
  　SELECT(
  　Grandchild [id],
  　IN([Parent_id],[Related Parents] )
  　)
  　)

As always, thank you very much for helping me!