{"id":1533,"date":"2021-09-21T08:18:33","date_gmt":"2021-09-21T15:18:33","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/azure-sdk\/?p=1533"},"modified":"2022-04-07T06:13:53","modified_gmt":"2022-04-07T13:13:53","slug":"announcing-the-preview-release-for-azure-tables-for-go","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/azure-sdk\/announcing-the-preview-release-for-azure-tables-for-go\/","title":{"rendered":"Announcing the Preview Release for Azure Tables for Go"},"content":{"rendered":"

We\u2019re excited to announce that the Azure Tables<\/strong><\/a> library’s first beta for Go<\/a> is now in preview release. The Azure Table service stores NoSQL data in the cloud with a key\/attribute store schema-less design. The Table storage service can be used to store flexible data sets, such as, user data for web applications, address books, device information, or other types of metadata.<\/p>\n

The new libraries follow our Azure SDK Guidelines<\/a>, making for an idiomatic, consistent, approachable, diagnosable, and dependable library. The new libraries use the language-specific Azure Core packages for handling requests, errors, and credentials.<\/p>\n

Note: The Azure Tables libraries are capable of targeting both Azure Storage Table and Azure Cosmos DB Table API<\/a> endpoints.<\/p>\n

SDK Availability<\/h2>\n

The Azure Tables libraries can be downloaded using:<\/p>\n

go get github.com\/Azure\/azure-sdk-for-go\/sdk\/data\/aztables<\/code><\/pre>\n
This blog post assumes you have a working developer environment for Go 1.16 and above and you already have an Azure Storage or Cosmos Table account. “`<\/p>\n
Creating the clients<\/h3>\n
There are two clients for interacting with the service. The ServiceClient<\/code> can be used for account-level interactions (creating tables, setting and getting access policies) and the Client<\/code> is used for table-level interactions (create or delete an entity, query, or list entities). You can create clients with an account key, Shared Access Signature, or using a connection string, all of which can be found in the Azure portal<\/a>. Throughout the examples, the handle(err)<\/code> function is used to demonstrate where you can insert your own error handling logic.<\/p>\n
cred, err := aztables.NewSharedKeyCredential(\"myAccountName\", \"myAccountKey\")\r\nhandle(err)\r\noptions := &aztables.ClientOptions{} \/\/Optional configuration of the Transporter, Retry policies, Telemetry options, or PerCallOptions\r\nclient, err := aztables.NewClient(\"https:\/\/myAccountName.table.core.windows.net\/myTableName\", cred, options)\r\nhandle(err)\r\n\/\/ ServiceClients can be created in a very similar manner:\r\nserviceClient, err := aztables.NewServiceClient(\"https:\/\/myAccountName.table.core.windows.net\", cred, options)\r\nhandle(err)\r\n\r\n\/\/ You can also use a connection string to create a ServiceClient\r\nserviceClient, err := aztables.NewServiceClientFromConnectionString(\"my-connection-string\", azcore.AnonymousCredential(), options)\r\nhandle(err)<\/code><\/pre>\n
Create a table and add an entity to it<\/h3>\n
Table names can be any alphanumeric string between 3 and 63 characters. A table can be created from either the Client<\/code> or the ServiceClient<\/code>, the following snippets will show how to create one from a Client<\/code>.<\/p>\n
An Entity can contain up to 255 properties, with the three system properties of PartitionKey<\/code>, RowKey<\/code>, and Timestamp<\/code>. The first two properties must be provided on all entities and the Timestamp<\/code> property will be modified by the service. For more information, see the service documentation<\/a>. Entities can only be inserted and queried from the Client<\/code>. Entities are returned via JSON allowing customers to use normal JSON marshaling and unmarshaling techniques (map[string]interface{}<\/code>, map[string]json.RawMessage<\/code>, or a specific struct instance). The aztables<\/code> library also provides an EDMEntity<\/code> struct (and EDMGUID<\/code>, EDMBinary<\/code>, EDMInt64<\/code>, EDMDateTime<\/code> types) to make it easier to parse an entity to an object and to dynamically discover the object’s fields and data types at runtime.<\/p>\n
There are three ways to create an entity: a custom entity, using aztables.Entity<\/code>, and using aztables.EdmEntity<\/code>.<\/p>\n
cred, err := aztables.NewSharedKeyCredential(\"myAccountName\", \"myAccountKey\")\r\nhandle(err)\r\nclient, err := aztables.NewClient(\"https:\/\/myAccountName.table.core.windows.net\/myTableName\", cred, nil)\r\nhandle(err)\r\n\r\nresp, err := client.Create(context.Background())\r\nhandle(err)\r\n\r\nmyEntity3 := aztables.EDMEntity{\r\n    Entity: aztables.Entity{\r\n        PartitionKey: \"pencils\",\r\n        RowKey: \"id-003\",\r\n    },\r\n    Properties: map[string]interface{}{\r\n        \"Product\": \"Ticonderoga Pencils\",\r\n        \"Price\": 5.00,\r\n        \"Count\": aztables.EDMInt64(12345678901234),\r\n        \"ProductGUID\": aztables.EDMGUID(\"some-guid-value\"),\r\n        \"DateReceived\": aztables.EDMDateTime(time.Date{....}),\r\n        \"ProductCode\": aztables.EDMBinary([]byte{\"somebinaryvalue\"})\r\n    }\r\n}\r\n\r\nmarshalled3, err := json.Marshal(myEntity3)\r\nhandle(err)\r\n\r\nresp, err := client.AddEntity(context.Background(), marshalled3, nil)\r\nhandle(err)<\/code><\/pre>\n
Querying Table Entities<\/h3>\n
The Client<\/code> allows the user to create custom queries using OData filters. Check out the service documentation<\/a> for more information about creating filters.<\/p>\n
cred, err := aztables.NewSharedKeyCredential(\"myAccountName\", \"myAccountKey\")\r\nhandle(err)\r\nclient, err := aztables.NewClient(\"https:\/\/myAccountName.table.core.windows.net\/myTableName\", cred, nil)\r\nhandle(err)\r\n\r\nfilter := \"PartitionKey eq 'markers' or RowKey eq 'id-001'\"\r\noptions := &ListEntitiesOptions{\r\n    Filter: &filter,\r\n    Select: to.StringPtr(\"RowKey,Value,Product,Available\"),\r\n    Top: to.Int32Ptr(15),\r\n}\r\n\r\npager := client.List(options)\r\nfor pager.NextPage(context.Background()) {\r\n    resp := pager.PageResponse()\r\n    fmt.Printf(\"Received: %v entitiesn\", len(resp.Entities))\r\n\r\n    for _, entity := range resp.Entities {\r\n        var myEntity aztables.EDMEntity\r\n        err = json.Unmarshal(entity, &myEntity)\r\n        handle(err)\r\n\r\n        fmt.Printf(\"Received: %v, %v, %v, %vn\", myEntity.Properties[\"RowKey\"], myEntity.Properties[\"Value\"], myEntity.Properties[\"Product\"], myEntity.Properties[\"Available\"])\r\n    }\r\n}\r\n\r\nerr := pager.Err()\r\nhandle(err)<\/code><\/pre>\n
Batch Transactions<\/h3>\n
The Table service allows multiple entity operations (create, delete, update, and upsert) to be made in a single request using transactional batch operations. The transaction is an “all-or-nothing” approach, if there’s a failure in one of the operations, the entire operation will fail. A transaction can do a combination of create, delete, update, and upsert operations.<\/p>\n
Note: All operations within a transaction must target the same partition key. A row key can only be specified once in a transaction.<\/p>\n
cred, err := aztables.NewSharedKeyCredential(\"myAccountName\", \"myAccountKey\")\r\nhandle(err)\r\nclient, err := aztables.NewClient(\"https:\/\/myAccountName.table.core.windows.net\/myTableName\", cred, nil)\r\nhandle(err)\r\n\r\nbatch := make([]aztables.TableTransactionAction, 4)\r\n\r\ntype ProductEntity struct {\r\n    aztables.Entity\r\n    Product string\r\n    Price float32\r\n    Brand string\r\n}\r\n\r\nmyentity1 := ProductEntity{\r\n    aztables.Entity: aztables.Entity{\r\n        PartitionKey: \"Marker\",\r\n        RowKey: \"id-001\",\r\n    },\r\n    Product: \"Crayola Markers\",\r\n    Price: 1.99,\r\n    Brand: \"Crayola\",\r\n}\r\nmarshalled1, err := json.Marshal(myEntity1)\r\nhandle(err)\r\nbatch[0] = aztables.TransactionAction{ActionType: aztables.Add, Entity: marshalled1}\r\n\r\nmyentity2 := ProductEntity{\r\n    aztables.Entity: aztables.Entity{\r\n        PartitionKey: \"Pencil\",\r\n        RowKey: \"id-002\",\r\n    },\r\n    Product: \"Classic Pencils\",\r\n    Price: .99,\r\n    Brand: \"Ticonderoga\",\r\n}\r\nmarshalled2, err := json.Marshal(myEntity2)\r\nhandle(err)\r\nbatch[1] = aztables.TransactionAction{ActionType: aztables.Delete, Entity: marshalled2}\r\n\r\nmyentity3 := ProductEntity{\r\n    aztables.Entity: aztables.Entity{\r\n        PartitionKey: \"Pen\",\r\n        RowKey: \"id-003\",\r\n    },\r\n    Product: \"Pilot G2\",\r\n    Price: 4.99,\r\n    Brand: \"Pilot\",\r\n}\r\nmarshalled3, err := json.Marshal(myEntity3)\r\nhandle(err)\r\nbatch[2] = aztables.TransactionAction{ActionType: aztables.InsertMerge, Entity: marshalled3}\r\n\r\nmyentity4 := ProductEntity{\r\n    aztables.Entity: aztables.Entity{\r\n        PartitionKey: \"Eraser\",\r\n        RowKey: \"id-004\",\r\n    },\r\n    Product: \"Expo Eraser\",\r\n    Price: 3.49,\r\n    Brand: \"Expo\",\r\n}\r\nmarshalled4, err := json.Marshal(myEntity4)\r\nhandle(err)\r\nbatch[3] = aztables.TransactionAction{ActionType: aztables.UpdateReplace, Entity: marshalled4}\r\n\r\nresp, err := client.SubmitTransaction(context.Background(), batch, nil)\r\nhandle(err)<\/code><\/pre>\n
Conclusion<\/h2>\n
We hope this post was a valuable technical introduction to the Azure Table<\/code> service and what you can use today to build and ship rich experiences. We welcome feedback and suggestions, to submit an issue visit our GitHub repository<\/a><\/p>\n
References<\/h2>\n