SQL---count()函数结果为null时替换为0

SELECT
	city,
	COUNT(*) AS count
FROM
	entInfo
WHERE
	department = '江西商务厅'
AND city IN (
	'南昌市',
	'景德镇市',
	'萍乡市',
	'九江市',
	'新余市',
	'鹰潭市',
	'赣州市',
	'吉安市',
	'宜春市',
	'抚州市',
	'上饶市'
)
GROUP BY
	city

SELECT t.city,count(h.id) as count from 
(
 SELECT '南昌市' city UNION
 SELECT '景德镇市' city UNION
 SELECT '萍乡市' city UNION
 SELECT '九江市' city UNION
 SELECT '新余市' city UNION
 SELECT '鹰潭市' city UNION
 SELECT '赣州市' city UNION
 SELECT '吉安市' city UNION
 SELECT '宜春市' city UNION
 SELECT '抚州市' city UNION
 SELECT '上饶市' city
) t 
LEFT JOIN intInfo 
on t.city=h.city 
and h.department='江西商务厅'
GROUP BY t.city
ORDER BY count desc