Question

我有一个带有ORDER BY子句的命名查询：

`query OrdersByRequesterSort {
  description: "Select all orders by requester"
  statement:
      SELECT org.test.sample.Order
          WHERE (requester == _$requesterParam)
            ORDER BY [placeTimestamp DESC]
}`

我在看到的查询之后拍了一下：

https://hyperledger.github.io/composer/reference/query-language.html

当我尝试执行此查询时，我收到以下错误：

`
    {
  "error": {
    "statusCode": 500,
    "name": "Error",
    "message": "Error trying to query chaincode. Error: chaincode error (status: 500, message: Error: http: read on closed response body)",
    "stack": "Error: Error trying to query chaincode. Error: chaincode error (status: 500, message: Error: http: read on closed response body)\n    at channel.queryByChaincode.then.catch (/Users/bower/.nvm/versions/node/v6.3.0/lib/node_modules/composer-rest-server/node_modules/composer-connector-hlfv1/lib/hlfconnection.js:779:34)"
  }
}`

我做错了吗？这支持了吗？

提前致谢。

Answer 1

对于我的网络，我按时间戳命令从HistorianRecord返回查询：

query getAllHistorianRecords {
  description: "getTradeRelatedHistorianRecords"
  statement: 
    SELECT org.hyperledger.composer.system.HistorianRecord
      WHERE (transactionTimestamp > '0000-01-01T00:00:00.000Z')
        ORDER BY [transactionTimestamp ASC]
}

要使这个ORDER BY语句工作，我必须在CouchDB中创建一个索引。如果您使用脚本创建结构，则数据库应位于http://localhost:5984/_utils/#database/composerchannel/_all_docs。

curl -X POST --header 'Content-Type: application/json' --header 
'Accept: application/json' -d '
{
  "index": {
    "fields": [
      {
        "data.transactionTimestamp": "asc"
      }
    ]
  },
  "type": "json"
}' 'http://localhost:5984/composerchannel/_index'

此curl将创建一个索引，查询可用于启用ORDER BY

Answer 2

看起来您需要在CouchDB中为数据类型定义排序索引以使用ORDER BY。

详情请见： https://github.com/hyperledger/composer/issues/1640

ORDER BY不在命名查询

2 个答案: