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spring-data-mongodb 聚合问题

 3 years ago
source link: https://www.v2ex.com/t/778560
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V2EX  ›  MongoDB

spring-data-mongodb 聚合问题

  anthoy · 1 天前 · 313 次点击

我在 spring-data-mongodb 中使用聚合，目的是实现查询下面数据

{
    "name":"test1",
    "receivedDate":"2021-05-18 00:00:52",
}
{
    "name":"test2",
    "receivedDate":"2021-05-18 00:00:52",
}
{
    "name":"test3",
    "receivedDate":"2021-05-18 00:00:52",
}
{
    "name":"test4",
    "receivedDate":"2021-05-18 00:00:52",
}

目标是通过聚合查询出来结果如下:

{
	"name":["test1","test2","test3","test4"],
}

目前使用方式是这样子

GroupOperation group = Aggregation.group().push("name").as("name");

[
    {
        "_id": null,
        "name": [
            "test1",
            "test2",
            "test3",
            "test4",
            "test4"
        ]
    }
]

但我修改为使用动态添加的时候

        GroupOperation group = Aggregation.group();
        for (int i = 0; i < params.length; i++) {
            group.push(params[i]).as(params[i]);
        }

发现查询的结果为

[
    {
        "_id": null
    }
]

感觉动态 push 哪里并没有生效，查询了挺多的资料好像也没有找到，感觉使用人挺少的

  • 有没有大佬知道应该怎么写的？
  • 或者还有别的方式实现
  • 或者自己遍历会不会比使用聚合这个更加好？

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