Sorting database Null values

Source: Internet
Author: User

In the process of developing a database program, you often encounter a null problem when sorting, sometimes you want null values to be in front of you, and sometimes you want to be in the back row.

This article simply records the problem of NULL ordering for Oracle and MySQL.


Oracle Null value ordering :

Oracle provides a specialized approach to nulls first (last), which is easy to use.

Null value in front

SELECT * from Tb_test ORDER by LV nulls first

Null value in the last

SELECT * from Tb_test ORDER by LV nulls

Empty values in MySQL sort:

Null value in front

SELECT * FROM Tb_test ORDER by if (IsNull (LV), 0,1), LV

Null value in the last

SELECT * FROM Tb_test ORDER by if (IsNull (LV), 1,0), LV

All of the above are sorted by LV ascending, descending the same.

Sorting database Null values

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.