mysql - Pivot Table Using MySQL and Group Conact

Question

This is a Question related to my original question

Pivot Table Using MySQL

Data in the tables are saved like this now

I have two tables Triples and Tags

Triples Table has the following Columns

  id  PostID  TagID   Value
   1   1        1     Murder
   2   1        1     Theft
   3   2        2     Knife 
   4   2        2     Gun 

Tags Table has the following Columns

 id   TagName
  1   Incident
  2   Weapon

I am trying to write sql to create a Pivot Table with Dynamic Headers

Output should be like this

   PostID  Incident              Weapon        
       1   Murder,Theft        
       2                          Knifie,Gun 

I written a inefficient and partial sql query for this, Any help in writing this sql appreciated

   SET @sql = NULL;
     SELECT
       GROUP_CONCAT(DISTINCT
          CONCAT(
             'max(CASE WHEN TagName = ''',
              TagName,
              ''' THEN p.value END) AS `',
               TagName, '`'
               )
                ) INTO @sql
         FROM tags;


     SET @sql 
        = CONCAT('CREATE VIEW PostTags as SELECT p.postid, p.id, ', @sql, ' 
          from triples p
          left join tags t
            on p.tagid = t.id
            group by p.postid, p.id');

         PREPARE stmt FROM @sql;

     EXECUTE stmt;
     DEALLOCATE PREPARE stmt;