mysql函数

拼接函数：concat(str,‘拼接的字符’)
保留左边数据：LEFT(str,0)
保留右边数据：RIGHT(str,0)
判空函数并赋值：IFNULL(str,‘自定义’)
拼接函数：CONCAT_WS(str,str,…)
分组后拼接函数：GROUP_CONCAT(str,str…)

SELECT
	concat(LEFT(t2.task_time,4),'年') year,
	RIGHT(t2.task_time,5) date,
	IFNULL(GROUP_CONCAT( concat( t3.custom_inputs_name, '(', t3.num, t3.unit_name, ')' ) ),'暂无记录') detail,
CONCAT_WS(',',t2.image1,t2.image2,t2.image3) images
FROM
	tb_farming_plot t1
	LEFT JOIN tb_farming_manage t2 ON t2.record_id = t1.record_id
	LEFT JOIN tb_farming_manage_detail t3 ON t3.manage_id = t2.id 
GROUP BY
	t2.id 
HAVING
	count( t2.id  )>= 1
ORDER BY t2.task_time desc
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结果