spring mongo如何在本机mongo聚合查询中传递变量

Question

我需要进行聚合查询，

 MatchOperation matchOperation = Aggregation.match(new Criteria("age").is(20));
    String lookup = "{$lookup: {from: 'race', localField: 'carId',foreignField: 'carId', as: 'result',},},";
    String unwind = " {\n" +
            "    $unwind: {\n" +
            "      path: \"$result\",\n" +
            "    },\n" +
            "  },";
    String addField =  "{ $addFields: { speed: '$result.raceSpeed', time: '$result.raceResulttime', progress: '$result.progress',},},";
    String matchField = " {\n" +
            "    $match:\n" +
            "      {\n" +
            "        time: {\n" +
            "          $gt: 0,\n" +
            "        },\n" +
            "      },\n" +
            "  },";
    String projectField = " {\n" +
            "    $project: {\n" +
            "      rank: 0,\n" +
            "      age: 0,\n" +
            "      phone: 0,\n" +
            "      role: 0,\n" +
            "      carImage: 0,\n" +
            "      creationDate: 0,\n" +
            "      gender: 0,\n" +
            "      _id: 0,\n" +
            "      result: 0,\n" +
            "    },\n" +
            "  },";
    SortOperation sortOperation = Aggregation.sort(Sort.Direction.ASC,"time");
    Aggregation aggregation = Aggregation.newAggregation(
            matchOperation,
            new CustomAggregationOperation(lookup),
            new CustomAggregationOperation(unwind),
            new CustomAggregationOperation(addField),
            new CustomAggregationOperation(matchField),
            new CustomAggregationOperation(projectField),
            sortOperation
    );
    List<AggResult> outputs= mongoTemplate.aggregate(aggregation, "user",
            AggResult.class).getMappedResults();

我需要在比赛字段中处理一些变量，例如

 String matchField = " {\n" +
            "    $match:\n" +
            "      {\n" +
            "        time: {\n" +
            "          $gt: timevariable,\n" + <============== wanna pass timevariable here
            "        },\n" +
            "      },\n" +
            "  },";

我已经尝试过这里的逃生解决方案 在此处输入链接描述但没有成功， 如果有人可以提供帮助，我将不胜感激，谢谢

Answer 1

我的答案是，如果使用本机查询，传递给它的变量是

  String iamvairable = "177";
    System.out.println(iamvairable);
    String projectField = " {\n" +
            "    $project: {\n" +
            "      rank: 0,\n" +
            "      age: "+iamvairable+",\n" +
            "      phone: 0,\n" +
            "      role: 0,\n" +
            "      carImage: 0,\n" +
            "      creationDate: 0,\n" +
            "      gender: 0,\n" +
            "      _id: 0,\n" +
            "      result: 0,\n" +
            "    },\n" +
            "  },";
    System.out.println("test string - " + projectField);