extract highest row from array

RE: extract highest row from array

Peter Lewis — Thu, 04 Mar 2021 22:41:33 GMT

Yeah this will only work if it's actually a timestamp - there isn't a concept of a "MAX" for a text field, so it wouldn't be supported. Can you update the column in the database to use a timezone instead? I also don't think your filters are going to work if it's actually stored in the database as a text type.

RE: extract highest row from array

gauravp0003 — Thu, 04 Mar 2021 18:09:48 GMT

seems timestamp is getting stored in text format in DB and CDT is also having text

RE: extract highest row from array

gauravp0003 — Thu, 04 Mar 2021 18:06:18 GMT

Thank Peter. I have tried below code but it says MAX cannot be applied to timestamp (Expression evaluation error at function a!queryEntity [line 2]: Cannot apply aggregation function [MAX] to field [timestamp]. The valid data types for [MAX] are [[Number (Integer), Number (Decimal), Interval (Day to Second), Boolean, Date, Date with Timezone, Date and Time, Date and Time with Timezone, Time]].)

If i change MAX with count it says (Expression evaluation error at function a!queryEntity [line 2]: Cannot sort by [timestamp]. When grouping, provide the alias in order to sort by one of the grouped or aggregated fields.)

Snippet of code:

In output i want (username,firstname,timestamp(latest),created) from view.

with(
a!queryEntity(
entity: cons!VW,
query: a!query(
aggregation: a!queryAggregation(
aggregationColumns:
{
a!queryAggregationColumn(
field: "username",
isGrouping: true
),
a!queryAggregationColumn(
field: "timestamp",
alias:"last_login",
aggregationFunction: "COUNT"
)
}
),
logicalExpression: a!queryLogicalExpression(
operator: "AND",
filters: {
a!queryFilter(
field: "username",
operator: "in",
value: ri!user
),
a!queryFilter(
field: "timestamp",
operator: ">=",
value: ri!year & "-01-01 00:00:00"
),
a!queryFilter(
field: "timestamp",
operator: "<=",
value: ri!year & "-03-31 00:00:00"
)
}
),
pagingInfo: a!pagingInfo(1,-1,a!sortInfo("timestamp",false))
)
)
)

RE: extract highest row from array

Peter Lewis — Thu, 04 Mar 2021 17:28:50 GMT

You can do this using an aggregation. If you group by the username and return the MAX of the date, then it should return the most recent item. Here's an example:

a!queryEntity(
  entity: cons!YOUR_DSE,
  query: a!query(
    aggregation: a!queryAggregation(
      aggregationColumns: {
        a!queryAggregationColumn(
          field: "username",
          isGrouping: true
        ),
        a!queryAggregationColumn(
          field: "dateUpdated",
          alias: "dateUpdated_max",
          aggregationfunction: "MAX",
        )
      }
    ),
    pagingInfo: a!pagingInfo(
      startIndex: 1,
      batchSize: 50,
      sort: a!sortInfo(
        field: "dateUpdated_max",
        ascending: false
      )
    )
  ),
  fetchTotalCount: false
)

RE: extract highest row from array

gauravp0003 — Thu, 04 Mar 2021 17:01:08 GMT

Hello Manuel,

Thank you . Yes , using sort info i am able to get the top rows sorted in order but as said there are many rows in returned dataset and i want the latest top rows out to show in grid as unique data else multiple users are appearing in grid , i want unique usernames with latest timestamp.

RE: extract highest row from array

ManuelHTG — Thu, 04 Mar 2021 16:59:07 GMT

Does the Dataset comes from the DB?

If yes, you can use a!paginginfo and with the a!sort get the data in chronological order.