MySQL数据库结果集：

Department     Month      Value
Sale        February       50
Sale        March          35
Sale        April          65
Sale        May            120
Dispatch   February       85
Dispatch   March          23
Dispatch   April          45
Dispatch   May            33
.... etc

这是重复的所有四个部门。
我想让PHP格式化数据结果，所以看起来像这样：

['Month',   'Sales',  'Dispatch',   'Support', 'Calibration'],
['February', 50,     85,         15,      53],
['March',    35,     23,         12,      55],

等等
MySQL语句：

$sql_line_chart = "SELECT d.department as department, MONTHNAME(date_created) AS month, 
               COALESCE(SUM(CASE WHEN c.cat_id IN (5,6,7,8,9,10,11,12,13,15) THEN time_spent END), 0) as value
                FROM master AS m 
                 INNER JOIN category AS c ON c.cat_id = m.cat_id 
                  INNER JOIN department AS d ON d.dept_id = m.dept_id 
                  WHERE 
                  AND 
                  date_created > CURRENT_DATE - INTERVAL DAYOFYEAR(CURRENT_DATE) - 1 DAY 
                 AND  
                date_created < CURRENT_DATE - INTERVAL DAYOFYEAR(CURRENT_DATE) - 1 DAY + INTERVAL 1 YEAR 
               GROUP BY d.department, month 
              ORDER by d.department ASC, m.date_created ASC";