NATURAL_SORT_KEY

Syntax

NATURAL_SORT_KEY(str)

Description

The NATURAL_SORT_KEY function is used for sorting that is closer to natural sorting. Strings are sorted in alphabetical order, while numbers are treated in a way such that, for example, 10 is greater than 2, whereas in other forms of sorting, 2 would be greater than 10, just like z is greater than ya.

Example

CREATE TABLE t1 (c TEXT);

INSERT INTO t1 VALUES ('b1'),('a2'),('a11'),('a1');

SELECT c FROM t1;
+------+
| c    |
+------+
| b1   |
| a2   |
| a11  |
| a1   |
+------+

SELECT c FROM t1 ORDER BY c;
+------+
| c    |
+------+
| a1   |
| a11  |
| a2   |
| b1   |
+------+

Unsorted, regular sort and natural sort:

TRUNCATE t1;

INSERT INTO t1 VALUES 
  ('5.5.31'),('10.7.0'),('10.2.1'),
  ('10.1.22'),('10.3.32'),('10.2.12');

SELECT c FROM t1;
+---------+
| c       |
+---------+
| 5.5.31  |
| 10.7.0  |
| 10.2.1  |
| 10.1.22 |
| 10.3.32 |
| 10.2.12 |
+---------+

SELECT c FROM t1 ORDER BY c;
+---------+
| c       |
+---------+
| 10.1.22 |
| 10.2.1  |
| 10.2.12 |
| 10.3.32 |
| 10.7.0  |
| 5.5.31  |
+---------+

SELECT c FROM t1 ORDER BY NATURAL_SORT_KEY(c);
+---------+
| c       |
+---------+
| 5.5.31  |
| 10.1.22 |
| 10.2.1  |
| 10.2.12 |
| 10.3.32 |
| 10.7.0  |
+---------+

Sorting IPs, unsorted, regular sort and natural sort::

TRUNCATE t1;

INSERT INTO t1 VALUES 
  ('192.167.3.1'),('192.167.1.12'),('100.200.300.400'),
  ('100.50.60.70'),('100.8.9.9'),('127.0.0.1'),('0.0.0.0');

SELECT c FROM t1;
+-----------------+
| c               |
+-----------------+
| 192.167.3.1     |
| 192.167.1.12    |
| 100.200.300.400 |
| 100.50.60.70    |
| 100.8.9.9       |
| 127.0.0.1       |
| 0.0.0.0         |
+-----------------+

SELECT c FROM t1 ORDER BY c;
+-----------------+
| c               |
+-----------------+
| 0.0.0.0         |
| 100.200.300.400 |
| 100.50.60.70    |
| 100.8.9.9       |
| 127.0.0.1       |
| 192.167.1.12    |
| 192.167.3.1     |
+-----------------+

SELECT c FROM t1 ORDER BY NATURAL_SORT_KEY(c);
+-----------------+
| c               |
+-----------------+
| 0.0.0.0         |
| 100.8.9.9       |
| 100.50.60.70    |
| 100.200.300.400 |
| 127.0.0.1       |
| 192.167.1.12    |
| 192.167.3.1     |
+-----------------+