Aster nPath aggregate FIRST / LAST....extended

Aster
Enthusiast

Aster nPath aggregate FIRST / LAST....extended

Hi nPath experts, is it possible to get also an SECOND,THIRD,FOURTH, etc.....or LAST - 1, LAST - 2 etc...in an aggregation in a RESULT list from nPath? Considering the bank clicks example, with ANY PAGE as  A, PAGE = 'HELPDESK' as B, A+.B as pattern to have an result like:

 

sessionid, FIRST (page_index of (A)), SECOND (page_index of (A)), THIRD (page_index of (C)).....page_index of (B)

 

It's a transposition in chronological order of attributes of any consecutive elements of type A preceding B. 

 

Thanks

 

 

1 REPLY
Enthusiast

Re: Aster nPath aggregate FIRST / LAST....extended

Actually, this is an issue of Teradata Database implementation of nPath, the syntax that is missing compared to Aster nPath is:

 

NTH (
col_expr, n OF symbol_list )
Returns the col_expr value of the nth matched row, where n is a nonzero
value of the data type SMALLINT, INTEGER, or BIGINT.
The sign of n determines whether the nth matched row is nth from the
first or last matched row. For example, if n is 1, then the nth matched row
is the first matched row, and if n is -1, then the nth matched row is the last
matched row.
If n is greater than the number of matched rows, then the NTH function
returns NULL.