FIRST

Returns the first value of the aggregated key in the stream.
Syntax
FIRST(VALUE)
Arguments
VALUE: An expression of any type.
Returns
Returns a value of first VALUE for each each key in the statement aggregation.
The result type matches the VALUE.
Example
Data 
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[
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   {
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      "GROUP_ID":"G1",
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      "USER_ID":"U1",
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      "CONNECTION_TIME":"2020-06-26 02:31:29,573"
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   },
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   {
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      "GROUP_ID":"G1",
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      "USEr_ID":"U2",
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      "CONNECTION_TIME":"2020-06-26 18:11:45,783"
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   },
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   {
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      "GROUP_ID":"G2",
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      "USER_ID":"Z1",
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      "CONNECTION_TIME":"2020-06-26 23:54:27,687"
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   },
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   {
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      "GROUP_ID":"G2",
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      "CONNECTION_TIME":"2020-07-26 23:54:27,687"
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   },
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   {
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      "GROUP_ID":"G1",
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      "USER_ID":"U2",
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      "CONNECTION_TIME":"2021-07-01 02:31:29,573"
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   },
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   {
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      "GROUP_ID":"G1",
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      "USER_ID":"U1",
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      "CONNECTION_TIME":"2021-07-01 18:11:45,783"
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   },
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   {
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      "GROUP_ID":"G2",
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      "USER_ID":"Z1",
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      "CONNECTION_TIME":"2021-07-01 23:54:27,687"
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   }
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]
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Query
Find the first connection_time for each GROUP_ID and USER_ID:
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SELECT
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   data.GROUP_ID AS group_id:STRING,
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   data.USER_ID AS user_id:STRING,
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   FIRST(data.CONNECTION_TIME) AS first_data_connection_time:STRING 
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FROM
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   "SAMPLE_DATA_G1U1 - json" 
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GROUP BY
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   data.GROUP_ID,
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   data.USER_ID"
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Results
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{
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   "group_id":"G2",   ,
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   "2020-07-26 23:54:27,687"
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}{
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   "group_id":"G2",
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   "user_id":"Z1",
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   "first_data_connection_time":"2020-06-26 23:54:27,687"
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}{
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   "group_id":"G1",
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   "user_id":"U2",
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   "first_data_connection_time":"2020-06-26 18:11:45,783"
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}{
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   "group_id":"G1",
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   "user_id":"U1",
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   "first_data_connection_time":"2020-06-26 02:31:29,573"
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}
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Related Functions
​FIRST_ARRAY 
FIRST_EACH 
FIRST_TIME_SERIES 
LAST​
Dialog

DYNAMIC_SESSIONS

FIRST_ARRAY

Last modified 8mo ago

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