Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
MySQL update column to NULL for blank values
For this, you can use IF() along with UPDATE command. Let us first create a table −
mysql> create table DemoTable1601 -> ( -> FirstName varchar(20) , -> LastName varchar(20) -> ); Query OK, 0 rows affected (0.53 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1601 values('John','Doe');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable1601 values('Adam','');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable1601 values('David','Miller');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable1601 values('Chris','');
Query OK, 1 row affected (0.11 sec)Display all records from the table using select statement −
mysql> select * from DemoTable1601;
This will produce the following output −
+-----------+----------+ | FirstName | LastName | +-----------+----------+ | John | Doe | | Adam | | | David | Miller | | Chris | | +-----------+----------+ 4 rows in set (0.00 sec)
Following is the query to update column to null or its value −
mysql> update DemoTable1601 set LastName=if(LastName='',NULL,LastName); Query OK, 2 rows affected (0.22 sec) Rows matched: 4 Changed: 2 Warnings: 0
Let us check the table records once again −
mysql> select * from DemoTable1601;
This will produce the following output −
+-----------+----------+ | FirstName | LastName | +-----------+----------+ | John | Doe | | Adam | NULL | | David | Miller | | Chris | NULL | +-----------+----------+ 4 rows in set (0.00 sec)
Updated on: 16-Dec-2019
2K+ Views
Advertisements