Numbering functions

The following sections describe the numbering functions that BigQuery supports. Numbering functions are a subset of window functions. For an explanation of how window functions work, see Window function_calls. For a description of how numbering functions work and an example comparing RANK, DENSE_RANK, and ROW_NUMBER, see the Numbering function concepts.

OVER clause requirements:

PARTITION BY: Optional.
ORDER BY: Required, except for ROW_NUMBER().
window_frame_clause: Disallowed.

RANK

RANK()

Description

Returns the ordinal (1-based) rank of each row within the ordered partition. All peer rows receive the same rank value. The next row or set of peer rows receives a rank value which increments by the number of peers with the previous rank value, instead of DENSE_RANK, which always increments by 1.

Return Type

INT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  RANK() OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+-------------+
| name            | finish_time            | division | finish_rank |
+-----------------+------------------------+----------+-------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 1           |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 4           |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 1           |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 2           |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 3           |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 4           |
+-----------------+------------------------+----------+-------------+

DENSE_RANK

DENSE_RANK()

Description

Returns the ordinal (1-based) rank of each row within the window partition. All peer rows receive the same rank value, and the subsequent rank value is incremented by one.

Return Type

INT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  DENSE_RANK() OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+-------------+
| name            | finish_time            | division | finish_rank |
+-----------------+------------------------+----------+-------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 1           |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 3           |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 1           |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 2           |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 3           |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 4           |
+-----------------+------------------------+----------+-------------+

PERCENT_RANK

PERCENT_RANK()

Description

Return the percentile rank of a row defined as (RK-1)/(NR-1), where RK is the RANK of the row and NR is the number of rows in the partition. Returns 0 if NR=1.

Return Type

FLOAT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  PERCENT_RANK() OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+---------------------+
| name            | finish_time            | division | finish_rank         |
+-----------------+------------------------+----------+---------------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 0                   |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 0.33333333333333331 |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 0.33333333333333331 |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 1                   |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 0                   |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 0.33333333333333331 |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 0.66666666666666663 |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 1                   |
+-----------------+------------------------+----------+---------------------+

CUME_DIST

CUME_DIST()

Description

Return the relative rank of a row defined as NP/NR. NP is defined to be the number of rows that either precede or are peers with the current row. NR is the number of rows in the partition.

Return Type

FLOAT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  CUME_DIST() OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+-------------+
| name            | finish_time            | division | finish_rank |
+-----------------+------------------------+----------+-------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 0.25        |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 0.75        |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 0.75        |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 1           |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 0.25        |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 0.5         |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 0.75        |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 1           |
+-----------------+------------------------+----------+-------------+

NTILE

NTILE(constant_integer_expression)

Description

This function divides the rows into constant_integer_expression buckets based on row ordering and returns the 1-based bucket number that is assigned to each row. The number of rows in the buckets can differ by at most 1. The remainder values (the remainder of number of rows divided by buckets) are distributed one for each bucket, starting with bucket 1. If constant_integer_expression evaluates to NULL, 0 or negative, an error is provided.

Return Type

INT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  NTILE(3) OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+-------------+
| name            | finish_time            | division | finish_rank |
+-----------------+------------------------+----------+-------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 1           |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 1           |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 3           |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 1           |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 1           |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 2           |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 3           |
+-----------------+------------------------+----------+-------------+

ROW_NUMBER

ROW_NUMBER()

Description

Does not require the ORDER BY clause. Returns the sequential row ordinal (1-based) of each row for each ordered partition. If the ORDER BY clause is unspecified then the result is non-deterministic.

Return Type

INT64

Example

WITH finishers AS
 (SELECT 'Sophia Liu' as name,
  TIMESTAMP '2016-10-18 2:51:45' as finish_time,
  'F30-34' as division
  UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
  UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
  UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
  UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
  UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
  UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
  UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 2:59:01', 'F30-34')
SELECT name,
  finish_time,
  division,
  ROW_NUMBER() OVER (PARTITION BY division ORDER BY finish_time ASC) AS finish_rank
FROM finishers;

+-----------------+------------------------+----------+-------------+
| name            | finish_time            | division | finish_rank |
+-----------------+------------------------+----------+-------------+
| Sophia Liu      | 2016-10-18 09:51:45+00 | F30-34   | 1           |
| Meghan Lederer  | 2016-10-18 09:59:01+00 | F30-34   | 2           |
| Nikki Leith     | 2016-10-18 09:59:01+00 | F30-34   | 3           |
| Jen Edwards     | 2016-10-18 10:06:36+00 | F30-34   | 4           |
| Lisa Stelzner   | 2016-10-18 09:54:11+00 | F35-39   | 1           |
| Lauren Matthews | 2016-10-18 10:01:17+00 | F35-39   | 2           |
| Desiree Berry   | 2016-10-18 10:05:42+00 | F35-39   | 3           |
| Suzy Slane      | 2016-10-18 10:06:24+00 | F35-39   | 4           |
+-----------------+------------------------+----------+-------------+