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如何编写mongo查询来查询对象内的数组?

mongodb-query mongodb arrays

2

Segev Lahav · 技术社区 · 9 年前

[
  {
    dec: 5972,
    bin: [0,0,0,1,0,1,1,1,0,1,0,1,0,1,0,0]
  },
  {
    dec: 397250,
    bin: [1,1,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,1,0]
  },
  {
    dec: 5,
    bin: [0,1,0,1]
  },
  {
    dec: 123,
    bin: [0,1,1,1,1,0,1,1]
  }
]

如何查询数据库以提供其中数字为“0”和“1”的所有对象 bin 属性是平等的。

{
  dec: 5,
  bin: [0,1,0,1]
}

1 回复 | 直到 9 年前

1

gmode 9 年前

db.test.aggregate([
{
    $project: {
        dec: "$dec",
        bin: "$bin",
        original_bin: "$bin"
    }
},

{
    $unwind: "$bin"
},
{
    $group: {
        _id: {
            dec: "$dec",
            bin: "$bin",
            original_bin: "$original_bin"
        },

        total: {
            $sum: 1
        }
    }
},
{
    $group: {
        _id: {dec: "$_id.dec", original_bin: "$_id.original_bin"},
        sums: {
            $addToSet: "$total"
        }
    }
},
{
    $match: {
        sums: {
            $size: 1
        }
    }
},
{
    $project: {
        _id: 0,
        dec: "$_id.dec",
        bin: "$_id.original_bin"
    }
}
]);

我有这样的样本数据:

{"dec":1,bin: [0,0,0,1,0,1,1,1,0,1,0,1,0,1,0,0]}
{"dec":2,bin: [0,1,0,1,0,0]}
{"dec":3,bin: [1,0,1,0,1,0]}
{"dec":4,bin: [0,1,0,0]}
{"dec":5,bin: [0,0,0,1,1,1]}
{"dec":6,bin: [0,1]}

给定对样本数据的查询将返回所需的数组:

{ "dec" : 6, "bin" : [ 0, 1 ] }
{ "dec" : 3, "bin" : [ 1, 0, 1, 0, 1, 0 ] }
{ "dec" : 5, "bin" : [ 0, 0, 0, 1, 1, 1 ] }