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2021-12-10 08:59:04 +08:00 回复了 fangwenxue 创建的主题 › 问与答 › mongodb 分组如何返回所有字段 |
```
[
{
$group: {
_id: "$username",
amount: {$sum: 1},
items: {$push: "$$ROOT"}
}
}
]
```
push: https://docs.mongodb.com/manual/reference/operator/aggregation/push/#mongodb-group-grp.-push
$$ROOT: https://docs.mongodb.com/manual/reference/aggregation-variables/#mongodb-variable-variable.ROOT
[
{
$group: {
_id: "$username",
amount: {$sum: 1},
items: {$push: "$$ROOT"}
}
}
]
```
push: https://docs.mongodb.com/manual/reference/operator/aggregation/push/#mongodb-group-grp.-push
$$ROOT: https://docs.mongodb.com/manual/reference/aggregation-variables/#mongodb-variable-variable.ROOT
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