在mysql表的列中查找所有不同的值

Question

i have a mysql table like this :

+------+-------------+----------+
|  id  | name        | category |
+------+-------------+----------+
|    1 | product 1   |category-A| 
|    2 | product 2   |category-B| 
|    3 | product 3   |category-C| 
|    4 | product 4   |category-B| 
|    5 | product 5   |category-C|
|    6 | product 6   |category-A|
|    7 | product 7   |category-A|
|    8 | product 8   |category-C|
|    9 | product 9   |category-B|
+------+-------------+----------+

is there any function that returns sth like this?

category-A,category-B,category-C

note : new categories may be added later .

thanks .

Answer 1

SELECT GROUP_CONCAT(DISTINCT category ORDER BY category) FROM TableName

• SQLFiddle Demo
• MySQL GROUP_CONCAT()

OUTPUT

╔══════════════════════════════════╗
║              RESULT              ║
╠══════════════════════════════════╣
║ category-A,category-B,category-C ║
╚══════════════════════════════════╝

Answer 2

Use DISTINCT in your query, it eliminate duplicate entry

SELECT GROUP_CONCAT(DISTINCT category )
FROM your_table

Answer 3

Are you just looking for a unique list of all categories?

SELECT DISTINCT category FROM mytable

Answer 4

Try

SELECT DISTINCT columnName FROM table_name

This should give you result containing all different values from that column.