ORDER BY

The ORDER BY clause is used to order the data in ascending or descending order based on one or more columns in the SELECT statement.

Syntax

The basic syntax of the ORDER BY clause is as follows:

  1. SELECT column1, column2, ...
  2. FROM table_name
  3. ORDER BY column1 [ASC | DESC], column2 [ASC | DESC], ...;

The ORDER BY clause can be used with one or more columns. The ASC keyword is used to sort the data in ascending order (default), and the DESC keyword is used to sort the data in descending order.

Examples

Consider the following table named “system_metrics”:

  1. +-------+-------+----------+-------------+-----------+---------------------+
  2. | host  | idc   | cpu_util | memory_util | disk_util | ts                  |
  3. +-------+-------+----------+-------------+-----------+---------------------+
  4. | host1 | idc_a |     11.8 |        10.3 |      10.3 | 2022-11-03 03:39:57 |
  5. | host1 | idc_b |       50 |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  6. | host1 | idc_c |     50.1 |        66.8 |      40.8 | 2022-11-03 03:39:57 |
  7. | host1 | idc_e |     NULL |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  8. | host2 | idc_a |     80.1 |        70.3 |        90 | 2022-11-03 03:39:57 |
  9. +-------+-------+----------+-------------+-----------+---------------------+

To sort the data in ascending order based on the “memory_util” column, the following SQL query can be used:

  1. SELECT * FROM system_metrics
  2. ORDER BY memory_util ASC;

The result of the above query would be:

  1. +-------+-------+----------+-------------+-----------+---------------------+
  2. | host  | idc   | cpu_util | memory_util | disk_util | ts                  |
  3. +-------+-------+----------+-------------+-----------+---------------------+
  4. | host1 | idc_a |     11.8 |        10.3 |      10.3 | 2022-11-03 03:39:57 |
  5. | host1 | idc_b |       50 |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  6. | host1 | idc_e |     NULL |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  7. | host1 | idc_c |     50.1 |        66.8 |      40.8 | 2022-11-03 03:39:57 |
  8. | host2 | idc_a |     80.1 |        70.3 |        90 | 2022-11-03 03:39:57 |
  9. +-------+-------+----------+-------------+-----------+---------------------+

To sort the data in descending order based on the “disk_util” column, the following SQL query can be used:

  1. SELECT * FROM system_metrics
  2. ORDER BY disk_util DESC;

The result of the above query would be:

  1. +-------+-------+----------+-------------+-----------+---------------------+
  2. | host  | idc   | cpu_util | memory_util | disk_util | ts                  |
  3. +-------+-------+----------+-------------+-----------+---------------------+
  4. | host2 | idc_a |     80.1 |        70.3 |        90 | 2022-11-03 03:39:57 |
  5. | host1 | idc_c |     50.1 |        66.8 |      40.8 | 2022-11-03 03:39:57 |
  6. | host1 | idc_b |       50 |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  7. | host1 | idc_e |     NULL |        66.7 |      40.6 | 2022-11-03 03:39:57 |
  8. | host1 | idc_a |     11.8 |        10.3 |      10.3 | 2022-11-03 03:39:57 |
  9. +-------+-------+----------+-------------+-----------+---------------------+