mysql左连接约束条件放在哪

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	SELECT
	dev.device_id AS deviceId,
	dev.activation_time AS activationTime,
	dev.bot_name AS botName,
	count( c.id ) AS active	
FROM
	device_information dev
	LEFT JOIN click_data c ON dev.device_id = c.device_no 
	AND c.interface_function IN ( '*智能回复', '进行快速咨询 ', '提交维权委托', '取所有目录', '获取爱老联系人', '提交防诈骗讲座', '根据关键词获取法律条例数据集合', '根据关键词获取相关案例数据集合' ) 
	AND c.create_time BETWEEN '2021-02-04 00:00:00' 
	AND now( ) 
WHERE
	dev.is_del = '0'	
GROUP BY
	dev.device_id 
ORDER BY
	active DESC

如果不是要求所有表的约束条件的话，不用放在where中，而是直接在on 后边继续填写条件进行约束

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