Join multiple lines to one

I have a problem combining the results of multiple rows into one single row result by user id.

I get this result:

||userID||eventTypeID||COUNT(*)||  
||  1   ||    1      ||    1   ||  
||  1   ||    2      ||    1   ||  
||  2   ||    1      ||    1   ||   
||  3   ||    2      ||    1   ||

      

I would like it to turn out like this:

||userID||eventTypeID ONE||COUNT()||eventTypeID TWO||COUNT()||

      

etc.

I can't figure out how I do it, I've tried pivotSQL and concat, but I can't seem to get it to work.

My SQL query:

SELECT eventMatch.userID, eventMatch.eventTypeID, COUNT( * )   
FROM  `eventMatch` , activity, activityMatch  
WHERE eventMatch.activityID = activity.activityID  
AND activity.activityID = activityMatch.activityID  
AND activity.khID =1  
GROUP BY eventTypeID, userID  
ORDER BY userID ASC  

      

Hope someone can help, maybe this is easy, but I tried looking for solutions for 2 days :-)

Thank..

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2 answers


Try the following:

SELECT
  eventMatch.userID, 
  SUM(eventMatch.eventTypeID = 1) As TypeOne,
  SUM(eventMatch.eventTypeID = 2) As TypeTwo, 
  COUNT( * )   
FROM  `eventMatch` 
INNER JOIN activity      ON eventMatch.activityID = activity.activityID 
INNER JOIN activityMatch ON activity.activityID = activityMatch.activityID  
WHERE activity.khID =1  
GROUP BY userID  
ORDER BY userID ASC;

      


Update 1

For several types of events, you can do it dynamically like this:

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT CONCAT('SUM(IF(em.eventTypeID = ''',
      em.eventTypeID, ''', 1, 0)) AS Type',
      em.eventTypeID )
  ) INTO @sql
FROM  `eventMatch`       AS em;

SET @sql = CONCAT('SELECT em.userID, ', @sql,
                  ', COUNT( * )   
                  FROM  `eventMatch`       AS em
                  INNER JOIN activity      AS  a ON em.activityID = a.activityID 
                  INNER JOIN activityMatch AS am ON a.activityID = am.activityID  
                  GROUP BY em.userID  
                  ORDER BY em.userID ASC  ;');

prepare stmt 
FROM @sql;

execute stmt;

      



SQL Fiddle Demo


Update 2

If you want to exclude all types from the table EventTypes

, even if this type does not have matches in the other table, you should get the list of types dynamically in the first step from this table EventTypes

instead of getting them from the table eventmatch

, execute the dynamic query in the same way as before. Like this:

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT CONCAT('SUM(IF(em.eventTypeID = ''',
      em.eventTypeID, ''', 1, 0)) AS Type',
      em.eventTypeID )
  ) INTO @sql
FROM  eventTypes       AS em; -- <---------- this is what I changed.


SET @sql = CONCAT('SELECT em.userID, ', @sql,
                  ', COUNT( * )   
                  FROM  `eventMatch`       AS em
                  INNER JOIN activity      AS  a ON em.activityID = a.activityID 
                  INNER JOIN activityMatch AS am ON a.activityID = am.activityID  
                  GROUP BY em.userID  
                  ORDER BY em.userID ASC  ;');

prepare stmt 
FROM @sql;

execute stmt;

      

Updated version of SQL Fiddle

+2


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does

GROUP BY eventMatch.userID, eventMatch.eventTypeID

      



the task?

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