Comma separated values in mysql

MY SQL:

GROUP_CONCAT function concatenates values within each group defined by GROUP BY clause.

Syntax	GROUP_CONCAT([DISTINCT] exp [ORDER BY sorting] [SEPARATOR ‘sep’])
Quick Example	SELECT GROUP_CONCAT(city) FROM cities GROUP BY state;
Separator	Comma (,) by default, ” eliminates separator
NULL Values	Skipped
Max Length	1024 by default, specified by group_concat_max_len system variable

Sample:

CREATE TABLE cities
   (
     city VARCHAR(70),
     state CHAR(2)
   );
 
   INSERT INTO cities VALUES ('San Francisco', 'CA');
   INSERT INTO cities VALUES ('San Diego', 'CA');
   INSERT INTO cities VALUES ('Los Angeles', 'CA');
 
   INSERT INTO cities VALUES ('Austin', 'TX');
   INSERT INTO cities VALUES ('Houston', 'TX');

   SELECT state, GROUP_CONCAT(city)
   FROM cities
   GROUP BY state;
The result:

CA	San Francisco,San Diego,Los Angeles
TX	Austin,Houston

SQL Server:

SELECT state,
STUFF((SELECT ',' + city FROM cities WHERE state = c.state FOR XML PATH('')),1 ,1 ,'')
FROM cities c
GROUP BY state

Hope this help !
Rahul Bhatia