MySQL column to row conversion and year-month grouping example

SELECT count(DISTINCT(a.rect_id)) zcount, a.job_dept,

 DATE_FORMAT(submit_date, '%Y-%m') zsubmit_date

 FROM

 Table Namea

 WHERE

 a.status = 3

 AND a.rstatu = 2

 AND a.job_dept IN ('19', '20', '21')

 GROUP BY

 a.job_dept,

 DATE_FORMAT(submit_date, '%Y-%m')

SELECT      
zsubmit_date,      
MAX(CASE WHEN job_dept = '19' THEN zcount ELSE 0 END ) 19zcount,      
MAX(CASE WHEN job_dept = '20' THEN zcount ELSE 0 END ) 20zcount,      
MAX(CASE WHEN job_dept = '21' THEN zcount ELSE 0 END ) 21zcount  

FROM    
(     
SELECT       
count(DISTINCT(a.rect_id)) zcount, a.job_dept,        
DATE_FORMAT(submit_date, '%Y-%m') zsubmit_date     
FROM       
Table Namea     
WHERE       
a.status = 3       
AND a.rstatu = 2       
AND a.job_dept IN ('19', '20', '21')     
GROUP BY     
a.job_dept,     
DATE_FORMAT(submit_date, '%Y-%m')    
) q GROUP BY    
zsubmit_date