hapjin

Technology is a powerful force in our society. Data, software,and communication can be used for bad: to entrench unfair power structures, to undermine human rights, and to protect vested interests. But they can also be used for good: to make underrepresented people's voice heard, to create opportunities for everyone, and to avert disasters. We are dedicated to working toward the good.

2017年11月19日

摘要： MongoDB二个主要的操作：一个是查询，另一个是统计。对于查询而言，主要是find()方法，再配合Filters组合多个查询条件。对于统计而言，则主要是aggregate操作，比如 group、sum、avg、project、match…… aggregate可以将上述操作组织成 pipelin 阅读全文

posted @ 2017-11-19 12:11 大熊猫同学阅读(4127) 评论(0) 推荐(0) 编辑

hapjin

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