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
Use MySQL to find duplicates and display in a single line
For this, you can use GROUP_CONCAT() along with GROUP BY clause. Both are used to group concat duplicates and display in a single line. Let us first create a table −
mysql> create table DemoTable ( StudentFavouriteSubject varchar(40), StudentName varchar(40) ) ; Query OK, 0 rows affected (0.75 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values('MySQL','Chris');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable values('MongoDB','Bob');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable values('MySQL','Sam');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values('Java','Mike');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values('C','Carol');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable values('MongoDB','John');
Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+-------------------------+-------------+ | StudentFavouriteSubject | StudentName | +-------------------------+-------------+ | MySQL | Chris | | MongoDB | Bob | | MySQL | Sam | | Java | Mike | | C | Carol | | MongoDB | John | +-------------------------+-------------+ 6 rows in set (0.00 sec)
Following is the query to find duplicates and display in a single line −
mysql> select group_concat(StudentName),StudentFavouriteSubject from DemoTable group by StudentFavouriteSubject;
This will produce the following output −
+---------------------------+-------------------------+ | group_concat(StudentName) | StudentFavouriteSubject | +---------------------------+-------------------------+ | Carol | C | | Mike | Java | | Bob,John | MongoDB | | Chris,Sam | MySQL | +---------------------------+-------------------------+ 4 rows in set (0.00 sec)
Updated on: 09-Oct-2019
197 Views
Advertisements