SELECT date as date, IFNULL(tab.num, 0) as num FROM (
# 生成月份表 @符号定义一个变量，而不是识别为列名
SELECT
	DATE_FORMAT(@cdate := date_add( @cdate, INTERVAL - 1 MONTH ),'%Y-%m') as date
FROM
	( 
	SELECT @cdate := date_add(CURDATE(), INTERVAL 1 MONTH )
	FROM fault LIMIT 12)d
	ORDER BY date
)date_c LEFT JOIN (
# 查询数据
SELECT COUNT(*) as num, DATE_FORMAT(fault_time,'%Y-%m') as t
FROM fault WHERE 1=1 GROUP BY DATE_FORMAT(fault_time,'%Y-%m')
)tab ON t=date

解释：

注意：FROM fault LIMIT 12中的表fault，数据必须大于12，否则会出错，可以换成数据量一定大于12的表

fault 为要查询的表

fault_time 为筛选的时间列