# 查询
## 请求体 json
::: details 查看代码
```
{
  "Cascade": [
    {
      "Cascade": [
        null
      ],
      "Distinct": true,
      "Filters": "string",
      "Group": {
        "AvgList": [
          "string"
        ],
        "Count": true,
        "MaxList": [
          "string"
        ],
        "MinList": [
          "string"
        ],
        "NameList": [
          "string"
        ],
        "SumList": [
          "string"
        ]
      },
      "Name": "string",
      "Orders": "name asc, createTime desc",
      "Projection": [
        "string"
      ]
    }
  ],
  "Distinct": true,
  "Filters": "string",
  "Group": {
    "AvgList": [
      "string"
    ],
    "Count": true,
    "MaxList": [
      "string"
    ],
    "MinList": [
      "string"
    ],
    "NameList": [
      "string"
    ],
    "SumList": [
      "string"
    ]
  },
  "Orders": "name asc, createTime desc",
  "PageNumber": 1,
  "PageSize": 50,
  "Projection": [
    "string"
  ]
}
```
:::

## 应答 json
::: details 查看代码
```metadata json
{
    "Content":[
        {
            "EquipID":"Eq3702020002f9052971335b417b896c73bdcd832f2d",
            "EquipLocalId":"CCTV-15F-06-05",
            "BimId":"Pj37020200023d180a0a876a11eaad60abc9d54aea48F20:8240980",
            "BimLocation":"-106089.73,64853.35,92300.0"
        }
    ],
    "Message":"接口失败会返回原因",
    "PageNumber":1,
    "PageSize":50,
    "Result":"success",
    "Total":1
}
```
::: 
## 分页

PageNumber 请求页码 Int 值 默认 1

PageSize 请求条数 Int 值 默认 50 条

通用接口中 PageSize 请求条数最大为 1000，为了避免大量的数据请求占用过多的资源，减少带宽

## 过滤条件
Filters 中编写过滤条件 例如：
```metadata json
{
  "Filters": "ProjectId = 'Pj3702020002'; Category = 'FSSN' ",
  "PageNumber": 1,
  "PageSize": 50
}
```
分号（;代表 and ）还可以使用 and 来查询，例如：
```metadata json
{
  "Filters": "ProjectId = 'Pj3702020002' and Category = 'FSSN' ",
  "PageNumber": 1,
  "PageSize": 50
}

```
更多详细查询条件以及操作符使用参考 [ “过滤条件” 操作符介绍](./filters)

## 排序
Orders 排序，默认升序 asc 可以多字段排序，升序 asc  降序 desc，例如：

```metadata json
{
  "Filters": "ProjectId = 'Pj3702020002' and Category = 'FSSN' ",
  "PageNumber": 1,
  "PageSize": 50,
  "Orders": "EquipName, CreateTime desc"
}
```
多字段排序从前往后依次按照 Orders 中的条件排序返回结果。

## 指定应答属性
Projection 指定后返回的属性，有些时候并不想把某些对象所有信息点都查出来，只是用几个属性，提高数据交互质量可以指定需要的属性，例如：
```metadata json
{
  "Filters": "ProjectId = 'Pj3702020002' and Category = 'FSSN' ",
  "PageNumber": 1,
  "PageSize": 50,
  "Projection": [
      "EquipID","EquipName","EquipLocalId","EquipLocalName","Category"
    ]
}
```
如上面的请求体就会返回 Projection 中指定的属性

## 去重
数据统计的时候会用到这个功能，比如统计某一个楼层下有多少种设备类型
``` 
{
  "Distinct": true,
  "Filters": "ProjectId = 'Pj4101020002';FloorId = 'Fl410102000212f498f8128147a7bfdb853e80bd5596'",
  "PageNumber": 1,
  "PageSize": 50,
  "Projection": [
    "Category"
  ]
}
```
返回结果
```metadata json
{
  "Content": [
    {
      "Category": "AEOV"
    },
    {
      "Category": "ATFC"
    }
  ],
  "Message": "",
  "PageNumber": 1,
  "PageSize": 2,
  "Result": "success",
  "Total": 20
}
```
去重是不根据 Projection 指定返回的属性去重的，如果返回的字段中包含id,是无法去重的，因为id通常是唯一的，去重是根据指定返回的字段为一个从整体去重的。

## 级联查询 
级联查询：在查询某一个对象的时候想要知道和这个对象有关系的有哪些对象，可以通过级联查询来操作，例如查询设备，以及所在的业务空间：
请求体
```
{
  "Cascade": [
    {
      "Name": "zoneSpaceInBase"
    }
  ],
  "Filters": "ProjectId = 'Pj1101020002' and EquipID = 'Eq11010200020321acc7e6f311e88ca4e5a21975b346' ",
  "PageNumber": 1,
  "PageSize": 50
}
```
返回结果
```metadata json
{
  "Content": [
    {
      "BuildingId": "Bd110102000223fbec0accfb11e8a471b5d1be3b6dfe",
      "Category": "ATFU",
      "CreateTime": "2019-06-19 12:57:11",
      "EquipID": "Eq11010200020321acc7e6f311e88ca4e5a21975b346",
      "EquipLocalID": "ATFU-TOP-N",
      "EquipLocalName": "楼顶北新风机组",
      "EquipName": "新风机组-E5L73",
      "EquipQRCode": "9ca5b7b0daab49999d602ac4ccdcf105",
      "LastUpdate": "2020-08-18 15:20:57",
      "ProjectId": "Pj1101020002",
      "ZoneSpaceBaseIn": [
        {
          "BuildingId": "Bd110102000223fbec0accfb11e8a471b5d1be3b6dfe",
          "FloorId": "Fl1101020002fbdcd07ed5cb11e88bee4dbb551fd992",
          "LastUpdate": "2020-07-17 17:17:19",
          "ObjectType": "GeneralZone",
          "ProjectId": "Pj1101020002",
          "RoomFuncType": "311",
          "RoomID": "Sp11010200024fdbd800e0aa11e88bee13864ca4ba47",
          "RoomLocalID": "7F-A801-1",
          "RoomLocalName": "A-801总裁室",
          "RoomName": "空间-ISRWU",
          "RoomQRCode": "2012bb68-2c9a-4bcc-a9a4-e0128634bf65"
        }
      ]
    }
  ],
  "Message": "",
  "PageNumber": 1,
  "PageSize": 50,
  "Result": "success",
  "Total": 1
}
```
ZoneSpaceBaseIn 中的数据就是当前设备所在的业务空间

级联的关系数据也支持 Filters 条件查询 Orders 排序 Projection 指定返回的字段，去重 Distinct ，级联出来的空间对象内部还可以继续级联
```
{
  "Cascade": [
    {
        "Cascade": [
             "Name": "generalSystem"
         ],
      "Name": "zoneSpaceInBase"
    }
  ],
  "Filters": "ProjectId = 'Pj1101020002' and EquipID = 'Eq11010200020321acc7e6f311e88ca4e5a21975b346' ",
  "PageNumber": 1,
  "PageSize": 50
}
```
上面的例子是查询设备 ，设备坐在的业务空间，业务空间和系统的关系，返回结构和上面的类似，在空间的数据中会出现系统的实例数据

## 综合示例 
查询某一楼层下的低压开关柜设备，使用创建时间加设备 ID 排序升序，指定返回字段为 EquipID EquipName Category EquipLocalID EquipLocalName
返回数量为100条 ，顺便查出来设备所在的默认业务空间，设备下的部件，设备关联的资产，设备和竖井的关系实例，竖井指定返回id和名称，示例如下：

```metadata json
{
  "Cascade": [
    {
      "Filters": "ObjectType = 'GeneralZone'",
      "Name": "zoneSpaceInBase" 
    },
    {
      "Name": "component"    
    },
    {
      "Name": "property"    
    },
     {
      "Name": "shaft",
        "Projection": [
         "ShaftID", "ShaftName"
         ]   
     }
  ],
  "Filters": "ProjectId = 'Pj4101020002';FloorId = 'Fl410102000212f498f8128147a7bfdb853e80bd5596'; Category = 'TDLS'",
  "Orders": "CreateTime asc,EquipID asc",
  "PageNumber": 1,
  "PageSize": 50,
  "Projection": [
    "EquipID", "EquipName", "Category", "EquipLocalID", "EquipLocalName"
  ]
}
```
返回结果

```metadata json
{
    "Content":[
        {
            "Category":"TDLS",
            "EquipID":"Eq11010200020321acc7e6f311e88ca4e5a21975b346",
            "EquipLocalID":"ATFU-TOP-N",
            "EquipLocalName":"楼顶北低压开关柜",
            "EquipName":"低压开关柜-E5L73",
            "ZoneSpaceBaseIn":[
                {
                    "BuildingId":"Bd110102000223fbec0accfb11e8a471b5d1be3b6dfe",
                    "FloorId":"Fl1101020002fbdcd07ed5cb11e88bee4dbb551fd992",
                    "ObjectType":"GeneralZone",
                    "ProjectId":"Pj1101020002",
                    "RoomFuncType":"311",
                    "RoomID":"Sp11010200024fdbd800e0aa11e88bee13864ca4ba47",
                    "RoomLocalID":"7F-A801-1",
                    "RoomLocalName":"A-801室",
                    "RoomName":"空间-ISRWU",
                }
            ],
            "component":[
                {
                    "Category":"TDLSDW",
                    "EquipID":"Ec11010200020321acc7e6f311e88ca4e5a21975b303",
                    "EquipLocalID":"ATFU-TOP-N-0",
                    "EquipLocalName":"楼顶北低压开关柜抽屉"
                }
            ],
            "property":{
                "Category":"LSA",
                "EquipID":"Pe11010200020321acc7e6f311e88ca4e5a21975b340",
                "EquipLocalID":"ATFU-TOP-N",
                "EquipLocalName":"楼顶北低压开关柜"
            },
            "shaftList":[
                {
                    "ShaftID":"Sh11010200020321acc7e6f311e88ca4e5a21975b349",
                    "ShaftName":"楼梯间"
                }
            ]
        }
    ],
    "Message":"",
    "PageNumber":1,
    "PageSize":50,
    "Result":"success",
    "Total":1
}
```



