这是我的sql代码：

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'COALESCE(MAX(CASE WHEN delc = ''',
      delc,
      ''' then ''y'' end),''n'') AS ',
      delc
    )
  ) INTO @sql
FROM inputr;

SET @sql = CONCAT('SELECT tem, ', @sql, ' 
                  FROM inputr 
                  GROUP BY tem');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

当我执行这个命令的时候 mysql workbench 6.3 ，我得到 error code 1064 问题是什么？这是错误：

PREPARE stmt FROM @sql  Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'plan,COALESCE(MAX(CASE WHEN delc = 'sil' then 'y' end),'n') AS sil,COALE' at line 1    0.000 sec