LAST_EACH

Returns an array of last values in the time window, grouped by a sub-key. The statement is limited to a maximum number of values.

Syntax

LAST_EACH([MAX VALUES, ]GROUP, VALUE)

Arguments

MAX VALUES: limit of number of key\value elements in the output GROUP: field to aggregate by VALUE: field to sub-aggregate by

‌ Returns

For each key aggregated in the query the function returns an array or key\value pairs of LAST values.

Notes

This function is non-deterministic.

AVAILABLE IN

Output Type Availablity Aggregate No Explicit Lookup Table Yes Inline Joins\Lookups No

Example

Data

[
   {
      "GROUP_ID":"G1",
      "USER_ID":"U1",
      "CONNECTION_TIME":"2020-06-26 02:31:29,573"
   },
   {
      "GROUP_ID":"G1",
      "USER_ID":"U2",
      "CONNECTION_TIME":"2020-06-26 18:11:45,783"
   },
   {
      "GROUP_ID":"G2",
      "USER_ID":"Z1",
      "CONNECTION_TIME":"2020-06-26 23:54:27,687"
   },
   {
      "GROUP_ID":"G2",
      "CONNECTION_TIME":"2020-07-26 23:54:27,687"
   },
   {
      "GROUP_ID":"G1",
      "USER_ID":"U2",
      "CONNECTION_TIME":"2021-07-01 02:31:29,573"
   },
   {
      "GROUP_ID":"G1",
      "USER_ID":"U1",
      "CONNECTION_TIME":"2021-07-01 18:11:45,783"
   },
   {
      "GROUP_ID":"G2",
      "USER_ID":"Z1",
      "CONNECTION_TIME":"2021-07-01 23:54:27,687"
   }
]

Query

For each group get a list of users and their last connection time in the time window:

SET
   DATE_TIME = TO_DATE(data.CONNECTION_TIME);
SELECT
   data.GROUP_ID AS group_id:STRING,
   LAST_EACH(data.USER_ID, data.CONNECTION_TIME) AS last_each_data_user_id__data_connection_time 
FROM
   "SAMPLE_DATA_G1U1 - json" 
GROUP BY
   data.GROUP_ID

Results

{
   "last_each_data_user_iddata_connection_time":[
      {
         "key":"Z1",
         "value":"2021-07-01 23:54:27,687"
      }
   ],
   "group_id":"G2"
}{
   "last_each_data_user_iddata_connection_time":[
      {
         "key":"U1",
         "value":"2021-07-01 18:11:45,783"
      },
      {
         "key":"U2",
         "value":"2021-07-01 02:31:29,573"
      }
   ],
   "group_id":"G1"
}