Subgraph是ENS在The Graph上托管的ENS合约的索引和结构化数据访问服务。比起ENS的JavaScript库，它可以用来更加灵活的访问ENS数据，比如以下的使用场景：

https://docs.ens.domains/contract-api-reference/subgraphdata

1. 查询设置了某个TEXTS字段的用户，如设置了头像avatar的用户, 设置了email的用户, 或者其他更特殊的字段，如carrierId。 我们可以通过carrierId来判断使用了beagle chat手机客户端的用户。查询方法如下：

   {
     domains(where: {resolver_:{texts_contains:["carrierId"]}}) {
     name
     labelName
     resolver{
       texts
     }
     resolvedAddress{id}
    }
   }
   

   返回结果为：

   {
   "data": {
   "domains": [
     {
       "name": "tomas.eth",
       "labelName": "tomas",
       "resolver": {
       "texts": [
         "email",
         "carrierId"
         ]
     },
   "resolvedAddress": {
       "id": "0x2259c79c85141a59b9117c789a5ae09774b7572f"
       }
     },
     {
       "name": "liwei.beagles.eth",
       "labelName": "liwei",
       "resolver": {
         "texts": [
           "carrierId"
           ]
       },
       "resolvedAddress": {
         "id": "0xa37f4be5106ec699488e21e5412956f765e32b6e"
       }
     },
     {
       "name": "zeliang.beagle.eth",
       "labelName": "zeliang",
       "resolver": {
         "texts": [
           "carrierId",
           "avatar",
           "nickName"
         ]
         },
       "resolvedAddress": {
           "id": "0x2259c79c85141a59b9117c789a5ae09774b7572f"
           }
     }
   ]
   }
   }
   

2. 查询某个地址是否有ENS名字 注意id的字符串为小写字母。

   query getDomainForAccount {
   account(id: "0xc461d56919d1957692eb98dbb15ae23a3567d1bb") {
     registrations(first: 10, orderBy: expiryDate, orderDirection: desc) {
     domain {
       name
     }
     }
     id
   }
   }
   

   返回值为：

   {
   "data": {
     "account": {
       "registrations": [
           {
             "domain": {
                 "name": "beagles.eth"
             }
           },
           {
             "domain": {
                 "name": "lenspace.eth"
             }
           }
       ],
       "id": "0xc461d56919d1957692eb98dbb15ae23a3567d1bb"
     }
   }
   }
   

subgprah的查询地址为：

1. rinkeby testnet

   https://thegraph.com/hosted-service/subgraph/ensdomains/ensrinkeby

2. Ethereum Mainnet

   https://thegraph.com/hosted-service/subgraph/ensdomains/ens

   Graph的使用文档：

https://thegraph.com/docs/en/querying/graphql-api/

特别注意递归条件（nested entity filtering）的使用。