在从 Hyperledger Composer v0.18.0 到 v0.19.0 的查询中使用 ORDER BY 的 CouchDB 索引错误

Question

从 Hyperledger Composer v0.18.0 迁移到 v0.19.0 时，我在使用 ORDER BY 语句的查询中遇到 CouchDB 索引问题。

Context:

名为事件的简单资产：

asset Event identified by id {
    o String id
    o String name
    o EventType eventType
    o DateTime scheduledTime
    o EventStatus status
}

带有 ORDER BY 语句的查询：

query getScheduledEvents {
    description: "Select all the SCHEDULED Events"
    statement:
        SELECT event.network.assets.Event
            WHERE (status == 'SCHEDULED')
                ORDER BY [scheduledTime ASC]
}

HL Composer v0.18.0

使用 Composer v0.18.0 一切正常。我可以从 REST API 中查询事件，只需在 CouchDB 上创建此索引即可：

{
    "type": "json",
    "def": {
    "fields": [
            {
                "scheduledTime": "asc"
            }
        ],
        "partial_filter_selector": {}
     }
}

HL Composer v0.19.0

从 Composer v0.19.0（和 Fabric 1.1.0）开始，索引将在部署时自动生成，新索引如下所示：

{
    "type": "json",
    "def": {
        "fields": [
            {
                "\$class": "asc"
            },
            {
                "\$registryType": "asc"
            },
            {
                "\$registryId": "asc"
            },
            {
                "status": "asc"
            },
            {
                "scheduledTime": "asc"
            }
        ],
        "partial_filter_selector": {}
    }
}

现在，使用 Composer v0.19.0，查询相同的端点时出现以下错误：

{
"error": {
    "statusCode": 500,
    "name": "Error",
    "message": "2 UNKNOWN: error executing chaincode: transaction returned with failure: Error: Couch DB Error:no_usable_index,  Status Code:400,  Reason:No index exists for this sort, try indexing by the sort fields.",
    "code": 2,
    "metadata": {
        "_internal_repr": {}
    },
    "details": "error executing chaincode: transaction returned with failure: Error: Couch DB Error:no_usable_index,  Status Code:400,  Reason:No index exists for this sort, try indexing by the sort fields.",
"stack": "Error: 2 UNKNOWN: error executing chaincode: transaction returned with failure: Error: Couch DB Error:no_usable_index,  Status Code:400,  Reason:No index exists for this sort, try indexing by the sort fields.\n    at new createStatusError (/home/user/.nvm/versions/node/v8.11.1/lib/node_modules/composer-rest-server/node_modules/grpc/src/client.js:64:15)\n    at /home/user/.nvm/versions/node/v8.11.1/lib/node_modules/composer-rest-server/node_modules/grpc/src/client.js:583:15"
    }
}

删除生成的索引并创建旧索引无法解决问题，因为我仍然收到相同的错误。

有什么想法吗？谢谢！

Answer 1

我能够用类似的查询重新创建它，并发现我可以通过重新排列索引文档中的字段来让它工作。在您的情况下，它将安排如下：

{
    "type": "json",
    "def": {
        "fields": [
            {
                "\$class": "asc"
            },
            {
                "\$registryType": "asc"
            },
            {
                "\$registryId": "asc"
            },
            {
                "scheduledTime": "asc"
            },
            {
                "status": "asc"
            }
        ],
        "partial_filter_selector": {}
    }
}

我认为这与

的第3条中的解释有关

在从 Hyperledger Composer v0.18.0 到 v0.19.0 的查询中使用 ORDER BY 的 CouchDB 索引错误

CouchDB Index Error using ORDER BY in queries from Hyperledger Composer v0.18.0 to v0.19.0

couchdb

hyperledger

hyperledger-fabric

hyperledger-composer