mongodb
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## 常用查询
随机查询几条数据： db.<collection>.aggregate([{$sample:{size:3}}]).pretty()
分组计数：db.<collection>.aggregate([{“$group": {_id: "$<field_name>”, count:{$sum:1}}}])
mongodb.1585880676.txt.gz · Last modified: 2021/02/10 21:29 (external edit)
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