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mysqlcasegroup-concat

How to use GROUP_CONCAT with MAX(CASE WHEN...)?


I want to take result from this query but i have problem in using group_concat with max case.

SELECT
  t1.id,
  t1.name,
  MAX(CASE WHEN t2.code = t1.f_name THEN t2.name END) AS name2,
  MAX(CASE WHEN t2.code = t1.l_name THEN t2.name END) AS name3,
  MAX(CASE WHEN t2.code = t1.a_name THEN t2.name END) AS name4,
  GROUP_CONCAT(MAX(CASE WHEN FIND_IN_SET(t3.code,t1.vehicles) THEN t3.name END) AS car_owned)
  GROUP_CONCAT(MAX(CASE WHEN FIND_IN_SET(t3.code,t1.homes) THEN t3.name END) AS home_owned)
FROM
  first_table AS t1 LEFT JOIN second_table AS t2
  ON t2.code IN (t1.f_name, t1.l_name, t1.a_name)
  LEFT JOIN second_table AS t3 ON FIND_IN_SET(t3.code,t1.vehicles) > 0 OR FIND_IN_SET(t3.code,t1.homes) > 0
GROUP BY
  t1.id,
  t1.name

for any help thanks. fiddle is here


Solution

  • Try this

    SELECT
      t1.id,
      t1.name,
      CASE WHEN t2.code = t1.f_name THEN t2.name END AS name2,
      CASE WHEN t2.code = t1.l_name THEN t2.name END AS name3,
      CASE WHEN t2.code = t1.a_name THEN t2.name END AS name4,
      CASE WHEN FIND_IN_SET(t3.code,t1.vehicles) > 0 THEN GROUP_CONCAT(DISTINCT(t3.name END)) AS car_owned)
      CASE WHEN FIND_IN_SET(t3.code,t1.homes) > 0 THEN GROUP_CONCAT(DISTINCT(t3.name)) END AS home_owned)
    FROM
      first_table AS t1 LEFT JOIN second_table AS t2
      ON t2.code IN (t1.f_name, t1.l_name, t1.a_name)
      LEFT JOIN second_table AS t3 ON FIND_IN_SET(t3.code,t1.vehicles) > 0 OR FIND_IN_SET(t3.code,t1.homes) > 0
    GROUP BY
      t1.id,
      t1.name
    

    fiddle is here