mysql group sum concat 等转 mongo 查询语句 concat 拼接不对。

从来没用过 mongodb 转写不熟悉现在遇到如下情况 mysql 语句

SELECT `*`,GROUP_CONCAT(`invoice_number`) as `invoice_number_all`,ROUND(SUM(`invoice_amount`)/100,2) as `invoice_amount_all`,ROUND(SUM(`premium_amount`)/100,2) as `premium_amount_all` FROM `t_invoice` 
WHERE `id` != 0
GROUP BY `insurer_id`,`region_id`,`invoice_company_id`,`data_type`,`invoice_date`,`invoice_remark` 
ORDER BY `invoice_date` DESC LIMIT 0,15

mysql concat 拼接结果：

mongodb 查询语句

db.t_invoice.aggregate(
	{
		"$group": {
			_id: {
				insurer_id:"$insurer_id", 
				region_id: "$region_id", 
				invoice_company_id:"$invoice_company_id",
				data_type: "$data_type",
				invoice_date: "$invoice_date",
				invoice_remark: "$invoice_remark",
			},
			count:{$sum:1},
			"create_by": {"$first": "$create_by"},
			"invoice_date": {"$first": {$dateToString: {format: "%Y-%m-%d", "date": {"$add": [new Date(0), {"$multiply" : ["$invoice_date", 1000]}]}}}},
			"invoice_amount": {"$sum": {"$divide": ["$invoice_amount", 100]}},
			"invoice_number": {"$first": {"$concat": ["$invoice_number", "-"]}},
			"invoice_code": {"$first": "$invoice_code"},
			"invoice_company_name": {"$first": "$invoice_company_name"},
			"insurer_name": {"$first": "$insurer_name"},
			"premium_amount": {"$sum": "$premium_amount"},
			"region_name": {"$first": "$region_name"},		
			"invoice_remark": {"$first": "$invoice_remark"},		
		}
	}
)

mongo 查询拼接结果

结果很悲剧 无论我用 concat concatArrays 它都不是把分组里的拿出来，而是只拿一个，如何才能像 mysql 一样拿出分组后的结果来拼接呢？