MYSQL select once for row with same values -

mysql

my query far select different column_names 2 tables , put under same column respectively.

in selection table c, want select once column same value.
example: c_id has 3 rows consist of value 52, select first row encountered skip rest, same goes row value 41.

is possible achieve adjusting current query or should find way?

 table m                    table c  -----   -----  -----        -----   -----   ----- | m_id |m_date |m_siri|     | c_id | c_date| c_data|  -----   -----  -----        -----   -----   ----- |   1  | 02-13 |  1 |     |  52  | 01-12 |  xxx  |  -----   -----  -----        -----   -----   ----- |   2  | 10-13 |  1 |     |  41  | 11-13 |  yyy  |  -----   -----  -----        -----   -----   ----- |   3  | 11-13 |  2 |     |  41  | 12-13 |  zzz  |  -----   -----  -----        -----   -----   ----- |   4  | 04-14 |  1 |     |  52  | 08-14 |  eee  |  -----   -----  -----        -----   -----   ----- |   5  | 01-15 |  2 |     |  52  | 10-14 |  xxx  |  -----   -----  -----        -----   -----   -----  (select      m_id id, m_date date       m       m_siri='one'  order      m_date desc limit 2)  union  (select      c_id id, c_date date       c  order      c_date desc)  order date desc 

use distinct keyword getting once record multiple.

(select      m_id id, m_date date       m       m_siri='one'  order      m_date desc limit 2)  union  (select      distinct(c_id) id, c_date date       c  order      ch_date desc)  order date desc