userId:1,points:1, groupTime: {$dateFromString: { dateString: "$tmp", format: "%Y:%m:%dT%H:%M:%SZ", } } } }因?yàn)樯弦徊絧roject操作中,tmp為字符串?dāng)?shù)據(jù),最終的聚合結(jié)果需要時(shí)間戳(主要懶,不想在程序中進(jìn)行轉(zhuǎn)換操作). 因此,此處對$tmp進(jìn)行操作,轉(zhuǎn)換為時(shí)間類型數(shù)據(jù),即groupTime.(5) $group對...
www.dbjr.com.cn/article/1666...htm 2025-6-6