Question

使用postgreSQL连接器获得一个简单的Loopback API来检索票证和响应。门票和响应单独回复，但当我尝试将响应嵌入到票证模型中时，我得到以下错误。我已经尝试过遵循文档，并且我确信它在我的一段关系中是一件很简单的事情，但是无论我尝试什么，我都无法让它发挥作用。

任何帮助都将不胜感激。

https://docs.strongloop.com/display/public/LB/Embedded+models+and+relations#Embeddedmodelsandrelations-EmbedsMany

门票型号：

{
"name": "Ticket",          
"base": "PersistedModel",
"idInjection": true,
"options": {
    "postgresql": {
        "schema": "customer_service",
        "table": "tbl_ticket"
     }
},
"properties": {
    "description": {
      "type": "String",
      "required": true,
      "length": null,
      "precision": null,
      "scale": null,
      "postgresql": {
        "columnName": "description",
        "dataType": "text",
        "dataLength": null,
        "dataPrecision": null,
        "dataScale": null,
        "nullable": "NO"
      }
    },    
    "id": {
      "type": "Number",
      "id": 1,
      "required": true,
      "length": null,
      "precision": 32,
      "scale": 0,
      "postgresql": {
        "columnName": "id",
        "dataType": "integer",
        "dataLength": null,
        "dataPrecision": 32,
        "dataScale": 0,
        "nullable": "NO"
      }
    }
  },
  "validations": [],
  "relations": {
    "responses": {
      "type": "embedsMany",
      "model": "Response",
      "property": "embededResponses",
      "options": {
        "validate": true,
        "forceId": false
      }   
    }
  },
  "acls": [],
  "methods": {}
}

响应模型：

{
  "name": "Response",
  "base": "PersistedModel",
  "idInjection": true,  
  "options": {
    "postgresql": {
      "schema": "customer_service",
      "table": "tbl_response"
    }
  },
  "properties": {
    "notes": {
      "type": "String",
      "required": false,
      "length": null,
      "precision": null,
      "scale": null,
      "postgresql": {
        "columnName": "notes",
        "dataType": "text",
        "dataLength": null,
        "dataPrecision": null,
        "dataScale": null,
        "nullable": "YES"
      }
    },
    "ticketId": {
      "type": "Number",
      "required": true,
      "length": null,
      "precision": 32,
      "scale": 0,
      "postgresql": {
        "columnName": "ticket_id",
        "dataType": "integer",
        "dataLength": null,
        "dataPrecision": 32,
        "dataScale": 0,
        "nullable": "NO"
      }
    },
    "id": {
      "type": "Number",
      "id": 1,
      "required": true,
      "length": null,
      "precision": 32,
      "scale": 0,
      "postgresql": {
        "columnName": "id",
        "dataType": "integer",
        "dataLength": null,
        "dataPrecision": 32,
        "dataScale": 0,
        "nullable": "NO"
      }
    }
  },
  "validations": [],
  "relations": {
    "ticket": {
      "type": "belongsTo",
      "model": "Ticket",
      "foreignKey": "ticketId"
    }
  },
  "acls": [],
  "methods": {}
}

错误：

{  
    "error": {
      "name": "error",
      "status": 500,
      "message": "column \"embededresponses\" does not exist",
      "length": 126,
      "severity": "ERROR",
      "code": "42703",
      "position": "213",
      "file": ".\\src\\backend\\parser\\parse_expr.c",
      "line": "766",
      "routine": "transformColumnRef",
      "stack": "error: column \"embededresponses\" does not exist\n    at Connection.parseE (C:\\WebApp\\node_modules\\loopback-connector-postgresql\\node_modules\\pg\\lib\\connection.js:539:11)\n    at Connection.parseMessage (C:\\WebApp\\node_modules\\loopback-connector-postgresql\\node_modules\\pg\\lib\\connection.js:366:17)\n    at Socket.<anonymous> (C:\\WebApp\\node_modules\\loopback-connector-postgresql\\node_modules\\pg\\lib\\connection.js:105:22)\n    at Socket.emit (events.js:107:17)\n    at readableAddChunk (_stream_readable.js:163:16)\n    at Socket.Readable.push (_stream_readable.js:126:10)\n    at TCP.onread (net.js:538:20)"
    }
}

Answer 1

您的Ticket模型应具有以下关系部分：

"relations": {
    "Responses": {
      "type": "hasMany",
      "model": "Response",
      "foreignKey": "ticketId"
    }
  }

您的Response模型关系正确无误。

从文档中不太清楚嵌入关系是否适用于NoSQL数据库。对于传统的SQL数据库，请使用Has *关系类型。

要从REST API检索Ticket Responses，请使用包含过滤器：https://docs.strongloop.com/display/public/LB/Include+filter。

示例：localhost:3000/api/Tickets/{id}?filter[include]=responses

Answer 2

我被告知你可以使用与SQL数据源的嵌入式关系，但数据然后以stringified-JSON格式存储。

我已在https://docs.strongloop.com/display/LB/Embedded+models+and+relations添加了备注。

兰德

Strongloop PostgreSQL连接器嵌入式模型错误

2 个答案: