Azure Cosmos DB SDK for Go
Introduction
This client library enables client applications to connect to Azure Cosmos DB via the NoSQL API. Azure Cosmos DB is a globally distributed, multi-model database service.
Getting Started
Prerequisites
- Go versions 1.21 or higher
- An Azure subscription or free Azure Cosmos DB trial account
Note: If you don't have an Azure subscription, create a free account before you begin.
You can Try Azure Cosmos DB for free without an Azure subscription, free of charge and commitments, or create an Azure Cosmos DB free tier account, with the first 400 RU/s and 5 GB of storage for free. You can also use the Azure Cosmos DB Emulator with a URI of https://localhost:8081. For the key to use with the emulator, see how to develop with the emulator.
Create an Azure Cosmos DB account
You can create an Azure Cosmos DB account using:
Install the package
Authenticate the client
In order to interact with the Azure Cosmos DB service you'll need to create an instance of the Client
struct. To make this possible you will need a URL and key of the Azure Cosmos DB service.
Logging
The SDK can make use of azcore
's logging implementation to collect useful information for debugging your application. In order to make use of logs, one must set the environment variable "AZURE_SDK_GO_LOGGING"
to "all"
like outlined in this public document.
Once that is done, the SDK will begin to collect diagnostics. By default, it will output the logs to stdout
- printing directly to your console - and will record all types of events (requests, responses, retries). If you'd like to configure a listener that acts differently, the small snippet below shows how you could do so.
import (
"os"
azlog "github.com/Azure/azure-sdk-for-go/sdk/azcore/log"
)
f, err := os.Create("cosmos-log-file.txt")
handle(err)
defer f.Close()
azlog.SetListener(func(event azlog.Event, s string) {
f.WriteString(s + "\n")
})
azlog.SetEvents(azlog.EventRequest, azlog.EventResponse, azlog.EventRetryPolicy, azlog.EventResponseError)
Examples
The following section provides several code snippets covering some of the most common Azure Cosmos DB NoSQL API tasks, including:
Create Cosmos DB Client
The clients support different forms of authentication. The azcosmos library supports authorization via Microsoft Entra identities or an account key.
Using Microsoft Entra identities
import "github.com/Azure/azure-sdk-for-go/sdk/azidentity"
cred, err := azidentity.NewDefaultAzureCredential(nil)
handle(err)
client, err := azcosmos.NewClient("myAccountEndpointURL", cred, nil)
handle(err)
Using account keys
const (
cosmosDbEndpoint = "someEndpoint"
cosmosDbKey = "someKey"
)
cred, err := azcosmos.NewKeyCredential(cosmosDbKey)
handle(err)
client, err := azcosmos.NewClientWithKey(cosmosDbEndpoint, cred, nil)
handle(err)
Create Database
Using the client created in previous example, you can create a database like this:
databaseProperties := azcosmos.DatabaseProperties{ID: dbName}
response, err := client.CreateDatabase(context, databaseProperties, nil)
handle(err)
database, err := client.NewDatabase(dbName)
handle(err)
Create Container
Using the above created database for creating a container, like this:
properties := azcosmos.ContainerProperties{
ID: "aContainer",
PartitionKeyDefinition: azcosmos.PartitionKeyDefinition{
Paths: []string{"/id"},
},
}
throughput := azcosmos.NewManualThroughputProperties(400)
response, err := database.CreateContainer(context, properties, &azcosmos.CreateContainerOptions{ThroughputProperties: &throughput})
handle(err)
CRUD operation on Items
item := map[string]string{
"id": "1",
"value": "2",
}
marshalled, err := json.Marshal(item)
if err != nil {
log.Fatal(err)
}
container, err := client.NewContainer(dbName, containerName)
handle(err)
pk := azcosmos.NewPartitionKeyString("1")
id := "1"
itemResponse, err := container.CreateItem(context, pk, marshalled, nil)
handle(err)
itemResponse, err = container.ReadItem(context, pk, id, nil)
handle(err)
var itemResponseBody map[string]string
err = json.Unmarshal(itemResponse.Value, &itemResponseBody)
if err != nil {
log.Fatal(err)
}
itemResponseBody["value"] = "3"
marshalledReplace, err := json.Marshal(itemResponseBody)
if err != nil {
log.Fatal(err)
}
itemResponse, err = container.ReplaceItem(context, pk, id, marshalledReplace, nil)
handle(err)
patch := PatchOperations{}
patch.AppendAdd("/newField", "newValue")
patch.AppendRemove("/oldFieldToRemove")
itemResponse, err := container.PatchItem(context.Background(), pk, id, patch, nil)
handle(err)
itemResponse, err = container.DeleteItem(context, pk, id, nil)
handle(err)
Next steps
License
This project is licensed under MIT.
Provide Feedback
If you encounter bugs or have suggestions, please
open an issue and assign the Cosmos
label.
Contributing
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License
Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For
details, visit https://cla.microsoft.com.
When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate
the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to
do this once across all repos using our CLA.
This project has adopted the Microsoft Open Source Code of Conduct.
For more information see the Code of Conduct FAQ or
contact opencode@microsoft.com with any additional questions or comments.
![Impressions](https://azure-sdk-impressions.azurewebsites.net/api/impressions/azure-sdk-for-go/sdk/data/azcosmos/README.png)