Sreeni.OData.Transpiler.Azure.Cosmos 1.0.2

Sreeni.OData.Transpiler.Azure.Cosmos

Sreeni.OData.Transpiler.Azure.Cosmos is a .NET-based OData query translator specifically designed for Azure Cosmos DB.

It translates OData queries into Cosmos DB SQL queries, enabling seamless integration and query translation for Azure Cosmos DB.

Features

• Parse OData queries
• Convert OData queries to Cosmos DB SQL queries
• Support for common OData query options: $select, $filter, $orderby, $top, $skip, and $expand
• Support for nested fields in the select clause, filter expressions, and orderby expressions
• Execute translated queries against Azure Cosmos DB

Getting Started

Installation

To install the package, add the following dependency to your project:

dotnet add package Sreeni.OData.Transpiler.Azure.Cosmos

Usage

This package provides the necessary components to translate and execute OData queries against Azure Cosmos DB. The following steps outline how to use the package:

1. Create an instance of ODataAzureCosmosClient:
   • You can create an instance using either a CosmosClient object or a connection string.

using Microsoft.Azure.Cosmos; 
using Sreeni.OData.Transpiler.Azure.Cosmos;
// Using CosmosClient object 
var cosmosClient = new CosmosClient("your-cosmos-db-connection-string"); 
var client = new ODataAzureCosmosClient(cosmosClient, "your-database-name", "your-container-name");
// Using connection string 
var client = new ODataAzureCosmosClient("your-cosmos-db-connection-string", "your-database-name", "your-container-name");

2. Execute OData queries:
   • Use the GetItemByQueryAsync method to execute a query and get a single item.
   • Use the GetListByQueryAsync method to execute a query and get a list of items.

// Example OData query 
string odataQuery = "$select=Name,Age&$filter=Age gt 30&$orderby=Name&$top=10&$skip=5";
// Get a single item 
var item = await client.GetItemByQueryAsync(odataQuery);
// Get a list of items 
var items = await client.GetListByQueryAsync(odataQuery);

Implementation Details

The ODataAzureCosmosClient class uses the ODataAzureCosmosQueryTranslator to translate OData queries into Cosmos DB SQL queries. The translation process involves the following steps:

1. Parse the OData query:

   • The ODataQueryParser class parses the OData query string into an ODataQuery object.

2. Translate the OData query:

   • The ODataAzureCosmosQueryTranslator class translates the ODataQuery object into a Cosmos DB SQL query using various query visitors (SelectVisitor, FilterVisitor, OrderByVisitor, TopVisitor, SkipVisitor, ExpandVisitor).

3. Execute the translated query:

   • The ODataAzureCosmosClient class executes the translated query using the Azure Cosmos DB SDK.

Example

Here is a complete example of how to use the Sreeni.OData.Transpiler.Azure.Cosmos package:

using Microsoft.Azure.Cosmos; 
using Sreeni.OData.Transpiler.Azure.Cosmos; 
using System; using System.Threading.Tasks;

public class Program 
{ 
    public static async Task Main(string[] args) 
    { 
        var cosmosClient = new CosmosClient("your-cosmos-db-connection-string"); 
        var client = new ODataAzureCosmosClient(cosmosClient, "your-database-name", "your-container-name");
        string odataQuery = "$select=Name,Age&$filter=Age gt 30&$orderby=Name&$top=10&$skip=5";

        var items = await client.GetListByQueryAsync<YourEntityType>(odataQuery);

        foreach (var item in items)
        {
            Console.WriteLine(item);
        }
    }
}

License

This project is licensed under the MIT License.