In this article, order by and terms related to order by will be discussed.
Introduction -
- There are some instances where the tables are to be arranged in a chronological order.
- While the users use the select statement to retrieve rows, one cannot guarantee that the rows are arranged in an order.
- To solve this, order by clause is being used.
Basic syntax:
select
select_list
from
table_name
order by
Example: Sample table-Student
| Roll number |
Name |
Course |
| 111 |
Riya |
CSE |
| 112 |
Apoorva |
ECE |
| 113 |
Mina |
Mech |
| 114 |
Rita |
Biotechnology |
| 115 |
Veena |
Chemical |
| 116 |
Deepa |
EEE |
If a user wants to arrange the names in an order then the query must be written as follows:
select
roll number
name
course
from
student
order by name
The output is:
| Roll number |
Name |
Course |
| 112 |
Apoorva |
ECE |
| 116 |
Deepa |
EEE |
| 113 |
Mina |
Mech |
| 114 |
Rita |
Biotechnology |
| 111 |
Riya |
Biotechnology |
| 115 |
Veena |
Chemical |
Note that the table is arranged in ascending order by default using the order by clause.
ASC | DESC :
- A user can arrange the columns in ascending or descending order using ASC or DESC respectively.
- ASC arranges the columns from lowest to highest
- DESC arranges the columns from highest to lowest.
- If there is a NULL column in the table, it will be treated as the lowest value.