Functions binding Cosmos DB, C# -- 2

Sample Code
4. Extract specific json properties
5. Read multiple documents


4. Extract specific json properties
I was wondering how serialization works. From 4-1 to 4-6 below, all the samples use the document, code, and request query.

Target document in Cosmos DB

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name": "Accord", "class": "LX", "type": "Sedan", "engine": "TurboCharged", "transMission": "CVT", "horsePower": "192PS", "price": 23720 } ```

GetDocument.cs

``` using Microsoft.AspNetCore.Mvc; using Microsoft.Azure.WebJobs; using Microsoft.Azure.WebJobs.Extensions.Http; using Microsoft.AspNetCore.Http; using Microsoft.Extensions.Logging; namespace FunctionsCosmosDB { public static class GetDocument { [FunctionName("GetDocument")] public static IActionResult Run( [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = null)] HttpRequest req, [CosmosDB(databaseName: "VehicleSpec", collectionName: "Vehicles", ConnectionStringSetting = "CosmosDBConnection", Id = "{Query.id}")] VehicleList vehicleList, ILogger log) { log.LogInformation("C# HTTP trigger function processed a request."); return vehicleList != null ? (ActionResult)new OkObjectResult(vehicleList) : new BadRequestObjectResult("Please pass a name on the query string or in the request body"); } } } ```

Request query

``` http://localhost:7071/api/GetDocument?id=1af97a2a-3a53-96ec-c470-dc13622f1dc0 ```

4-1. Basic class
This is not involved in serialization. The point is that the class has only values "id", "maker", "name", while the Cosmos DB document has "id", "maker", "name", "class", "type", "engine", "transMission", "horsePower", "price". The return only includes "id", "maker", "name".

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { public Guid id { get; set; } public string maker { get; set; } public string name { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name": "Accord" } ```

4-2. Basic class with Capital value name

The class has values with capital letter, "Maker", "Name", but the Cosmos DB document includes values with small letter, "maker", "name", and the return includes values with small letter, which is the original Cosmos DB document.

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { public Guid id { get; set; } public string Maker { get; set; } public string Name { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name": "Accord" } ```

4-3. Basic class with different value name
Next one is very interesting. The class includes "id", "Maker", "Name2", the Cosmos DB document includes "id", "maker", "name", and the return includes "id", "maker", "name2":null. The Functions and class does not care upper/lower case. It always return the class values with lowercase.

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { public Guid id { get; set; } public string Maker { get; set; } public string Name2 { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name2": null } ```

4-4. Serialization

Serialization is used here. In this way, the return is the same as 4-1

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { [JsonProperty("id")] public Guid id { get; set; } [JsonProperty("maker")] public string Maker { get; set; } [JsonProperty("name")] public string Name { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name": "Accord" } ```

4-5. Serialization with Capital value name
Next one is also interesting. The class includes "id", "maker", "name", Jason properties include "id", "Maker", "name", the Cosmos DB document includes "id", "maker", "name", and the return includes "id", "Maker", "Name". Whether the return includes upper/lower case depends on Jason properties, even though the Cosmos DB document includes lower case.

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { [JsonProperty("id")] public Guid id { get; set; } [JsonProperty("Maker")] public string Maker { get; set; } [JsonProperty("Name")] public string Name { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "Maker": "Honda", "Name": "Accord" } ```

4-6. Serialization with different value name
When you set the different class value name from the Cosmos DB document name, you can get correct ones with correct Jason properties.

VehicleList.cs

``` using System; using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { [JsonProperty("id")] public Guid id { get; set; } [JsonProperty("Maker")] public string Maker2 { get; set; } [JsonProperty("Name")] public string Name2 { get; set; } } } ```

Return

``` { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "Maker": "Honda", "Name": "Accord" } ```

5. Read multiple documents
If you use DocumentClient, you can extract multiple documents. Contains cannot handle GUID, so this time id type is string. In this example, search query is defined as searchterm, searchterm2, searchterm3, but you can create complex query by utilizing this.

VehicleList.cs

``` using Newtonsoft.Json; namespace FunctionsCosmosDB { public class VehicleList { [JsonProperty("id")] public string id { get; set; } [JsonProperty("maker")] public string Maker { get; set; } [JsonProperty("name")] public string Name { get; set; } [JsonProperty("class")] public string Class { get; set; } [JsonProperty("type")] public string Type { get; set; } [JsonProperty("engine")] public string Engine { get; set; } [JsonProperty("transMission")] public string TransMission { get; set; } [JsonProperty("horsePower")] public string HorsePower { get; set; } [JsonProperty("price")] public int Price { get; set; } } } ```

GetDocumentClient.cs

``` using System; using System.Threading.Tasks; using Microsoft.AspNetCore.Mvc; using Microsoft.Azure.WebJobs; using Microsoft.Azure.WebJobs.Extensions.Http; using Microsoft.AspNetCore.Http; using Microsoft.Extensions.Logging; using Microsoft.Azure.Documents.Client; using Microsoft.Azure.Documents.Linq; using System.Linq; namespace FunctionsCosmosDB { public static class GetDocumentClient { [FunctionName("GetDocumentClient")] public static async Task<iactionresult> Run( [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req, [CosmosDB(databaseName: "VehicleSpec", collectionName: "Vehicles", ConnectionStringSetting = "CosmosDBConnection")] DocumentClient client, ILogger log) { var searchterm = req.Query["searchterm"]; var searchterm2 = req.Query["searchterm2"]; var searchterm3 = req.Query["searchterm3"]; if (string.IsNullOrWhiteSpace(searchterm)) { return (ActionResult)new NotFoundResult(); } Uri collectionUri = UriFactory.CreateDocumentCollectionUri("VehicleSpec", "Vehicles"); log.LogInformation($"Searching for: {searchterm}, {searchterm2}, {searchterm3}"); IDocumentQuery<vehiclelist> query = client.CreateDocumentQuery<vehiclelist>(collectionUri) .Where(p => p.id.Contains(searchterm) || p.Maker.Contains(searchterm2) || p.Name.Contains(searchterm3)) .AsDocumentQuery(); while (query.HasMoreResults) { foreach (VehicleList result in await query.ExecuteNextAsync()) { log.LogInformation(result.id); } } return query != null ? (ActionResult)new OkObjectResult(query) : new BadRequestObjectResult("Please pass a name on the query string or in the request body"); } } } ```

Request query

``` http://localhost:7071/api/GetDocumentClient?searchterm=d7b&searchterm2=Hyundai&searchterm3=Accord ```

Return

``` [ { "id": "d7b70f4a-6cb0-e56d-2c41-1698a5a2bb0b", "maker": "Honda", "name": "Civic", "class": "LX", "type": "Hatchback", "engine": "NA", "transMission": "6MT", "horsePower": "158PS", "price": 19450 }, { "id": "1af97a2a-3a53-96ec-c470-dc13622f1dc0", "maker": "Honda", "name": "Accord", "class": "LX", "type": "Sedan", "engine": "TurboCharged", "transMission": "CVT", "horsePower": "192PS", "price": 23720 }, { "id": "a273e3ad-058f-d456-2256-ff10baabcf5d", "maker": "Honda", "name": "Accord", "class": "Hybrid", "type": "Sedan", "engine": "TwoMotorHybrid", "transMission": "E-CVT", "horsePower": "181PS", "price": 25320 }, { "id": "343d27e7-261f-3a6f-3981-35610f2c7671", "maker": "Honda", "name": "Accord", "class": "EX", "type": "Sedan", "engine": "TurboCharged", "transMission": "10AT", "horsePower": "252PS", "price": 27620 }, { "id": "ef47cfc3-0639-cf06-904a-8db1ebf95cef", "maker": "Hyundai", "name": "Sonata", "class": "SE", "type": "Sedan", "engine": "NA", "transMission": "8AT", "horsePower": "185PS", "price": 22300 } ] ```