Azure Cosmos DB SQL-如何对内部json属性进行转义

Question

Okay I have spent hours trying to get this to work.

I have an inner property in my json that is a json object. However when a device sends me the data the json in Gateway_Info is delimited. This makes querying that inner object impossible (using dot notation)

Is there a way to remove the \\ character from that json string to make it valid json?

SELECT * FROM c

 {
        "Asset_Key": "1",
        "Defrost_Cycles": 0,
        "Freeze_Cycles": 0,
        "Float_Switch_Raw_ADC": 0,
        "Bin_status": 0,
        "Line_Voltage": 0,
        "ADC_Evaporator_Temperature": 0,
        "Mem_Sw": 0,
        "Freeze_Timer": 0,
        "Defrost_Timer": 0,
        "Water_Flow_Switch": 0,
        "ADC_Mid_Temperature": 0,
        "ADC_Water_Temperature": 0,
        "Ambient_Temperature": 1,
        "Mid_Temperature": 1,
        "Water_Temperature": 1,
        "Evaporator_Temperature": 1,
        "Gateway_Info": "{\"temp_sensor\":0.00,\"temp_pcb\":82.00,\"gw_uptime\":123912.00,\"gw_fw_version\":\"0.0.0\",\"gw_fw_version_git\":\"1-dirty\",\"gw_sn\":\"30\",\"heap_free\":10648.00,\"gw_sig_csq\":19.00,\"gw_sig_quality\":1,\"wifi_sig_strength\":0.00,\"wifi_resets\":0.00,\"modem_sim_iccid\":\"1\",\"modem_meid\":\"1\",\"modem_model\":\"1\"}",
        "ADC_Ambient_Temperature": 0
}

Answer 1

PreTrigger in cosmos db need to be defined in the code, since your data is sent by the device, so it won't work through PreTrigger .

So, as you mentioned in your comment ,I suggest you using Azure Function CosmosTrigger to process per document before it is inserted into cosmos db.

My sample document:

My Azure Function CosmosTrigger code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.Documents;
using Microsoft.Azure.Documents.Client;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace ProcessJson
{
    public class Class1
    {
        [FunctionName("DocumentUpdates")]
        public static void Run(
        [CosmosDBTrigger("db", "item", ConnectionStringSetting = "myCosmosDB")]
        IReadOnlyList<Document> documents,
        TraceWriter log)
        {
            String endpointUrl = "***";
            String authorizationKey = "***";
            String databaseId = "db";
            String collectionId = "item";

            DocumentClient client = new DocumentClient(new Uri(endpointUrl), authorizationKey); ;

            Document doc = documents[0];

            string gateway = doc.GetPropertyValue<string>("gateway");
            JObject o = JObject.Parse(gateway);

            doc.SetPropertyValue("gateway",o);

            client.ReplaceDocumentAsync(UriFactory.CreateDocumentUri(databaseId, collectionId, doc.Id), doc);

            log.Verbose("document Id " + doc.Id);
        }
    }
}

Insert Result: