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
Write a MySQL query to check if field exists and then return the result set?
To check if field exists and then to return the result set, you can use the below syntax −
show columns from yourTableName where field='yourColumnName';
Let us first create a table −
mysql> create table DemoTable ( UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserFirstName varchar(20), UserLastName varchar(20), UserAge int, UserAddress varchar(200), UserCountryName varchar(20) ); Query OK, 0 rows affected (0.67 sec)
Here is the query to check if field exists and then return the result set −
mysql> show columns from DemoTable where field='UserCountryName';
This will produce the following output −
+-----------------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------------+-------------+------+-----+---------+-------+ | UserCountryName | varchar(20) | YES | | NULL | | +-----------------+-------------+------+-----+---------+-------+ 1 row in set (0.01 sec)
Here is the case when the column does not exist −
mysql>show columns from DemoTable where field='Marks';
This will produce the following output −
Empty set (0.00 sec)
Updated on: 30-Jul-2019
233 Views
Advertisements