CODEWITHSUNDEEP
sqlpostgresqlaggregate-functions
Luis Henrique
Luis Henrique

Reputation: 771

ERROR: aggregate function calls cannot be nested - POSTGRESQL

I am trying to create a select with record history within 30 days, where the values column gets a count, I just wish it would add the values returned for each day.

QUERY

SELECT
    date_update AS Time,
    SUM(COUNT(values)) as "Value"
FROM
    tb_get_metrics
WHERE
    data_update >= CURRENT_DATE - 30
GROUP BY Time
ORDER BY Time

Example OUTPUT:

       Time                      Value
2019-10-14 09:46:54.789772        30
2019-10-15 09:46:54.789772        50
2019-10-16 09:46:54.789772        70

SELECT * FROM tb_get_metrics

  date_update(TimeStamp)        value(String)
2019-10-14 09:46:54.789772        apple
2019-10-14 09:46:55.789772        apple
2019-10-14 09:46:56.789772        apple
2019-10-14 09:46:57.789772        apple
2019-10-14 09:46:58.789772        apple
2019-10-14 09:46:59.789772        apple
2019-10-14 09:47:00.789772        apple
2019-10-14 09:46:01.789772        apple
2019-10-14 09:46:02.789772        apple
2019-10-14 09:46:03.789772        apple
2019-10-14 09:46:04.789772        apple
2019-10-14 09:46:05.789772        apple
2019-10-15 09:46:03.789772        potato
2019-10-15 09:46:04.789772        potato
2019-10-15 09:46:05.789772        potato
...

Upvotes: 1

Views: 1893

Answers (3)

richyen
richyen

Reputation: 9958

By truncating the times off the timestamps, you can focus only on the date, which is what your WHERE clause seeks to do:

postgres=# SELECT
    date_update::date AS "Date",
    COUNT(values) as "Count"
FROM
    tb_get_metrics
WHERE
    date_update::date >= CURRENT_DATE - 30
GROUP BY "Date"           
ORDER BY "Date";
    Date    | Count 
------------+-------
 2019-10-14 |    24
 2019-10-15 |     6
(2 rows)

Upvotes: 1

forpas
forpas

Reputation: 164064

Get the date part only from each timestamp to group by:

SELECT
    date_update::date AS Time,
    COUNT(values) AS "Value"
FROM tb_get_metrics
WHERE date_update >= CURRENT_DATE - 30
GROUP BY Time
ORDER BY Time

Upvotes: 1

klin
klin

Reputation: 121474

You need to round the times to dates:

SELECT
    date_update::date AS "Date",
    COUNT(values) as "Value"
FROM
    tb_get_metrics
WHERE
    data_update >= CURRENT_DATE - 30
GROUP BY Time
ORDER BY Time

Upvotes: 1

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