Get Metadata activity in Azure Data Factory or Azure Synapse Analytics

APPLIES TO: Azure Data Factory Azure Synapse Analytics

You can use the Get Metadata activity to retrieve the metadata of any data in Azure Data Factory or a Synapse pipeline. You can use the output from the Get Metadata activity in conditional expressions to perform validation, or consume the metadata in subsequent activities.

Create a Get Metadata activity with UI

To use a Get Metadata activity in a pipeline, complete the following steps:

1. Search for Get Metadata in the pipeline Activities pane, and drag a Fail activity to the pipeline canvas.

2. Select the new Get Metadata activity on the canvas if it is not already selected, and its Settings tab, to edit its details.

3. Choose a dataset, or create a new one with the New button. Then you can specify filter options and add columns from the available metadata for the dataset.

   

4. Use the output of the activity as an input to another activity, like a Switch activity in this example. You can reference the output of the Metadata Activity anywhere dynamic content is supported in the other activity.

   

5. In the dynamic content editor, select the Get Metadata activity output to reference it in the other activity.

   

Supported capabilities

The Get Metadata activity takes a dataset as an input and returns metadata information as output. Currently, the following connectors and the corresponding retrievable metadata are supported. The maximum size of returned metadata is 4 MB.

Supported connectors

File storage

Connector/Metadata	itemName (file/folder)	itemType (file/folder)	size (file)	created (file/folder)	lastModified1 (file/folder)	childItems (folder)	contentMD5 (file)	structure2 (file)	columnCount2 (file)	exists3 (file/folder)
Amazon S3	√/√	√/√	√	x/x	√/√	√	x	√	√	√/√
Amazon S3 Compatible Storage	√/√	√/√	√	x/x	√/√	√	x	√	√	√/√
Google Cloud Storage	√/√	√/√	√	x/x	√/√	√	x	√	√	√/√
Oracle Cloud Storage	√/√	√/√	√	x/x	√/√	√	x	√	√	√/√
Azure Blob storage	√/√	√/√	√	x/x	√/√	√	√	√	√	√/√
Azure Data Lake Storage Gen2	√/√	√/√	√	x/x	√/√	√	√	√	√	√/√
Azure Files	√/√	√/√	√	√/√	√/√	√	x	√	√	√/√
Microsoft Fabric Lakehouse	√/√	√/√	√	x/x	√/√	√	√	√	√	√/√
File system	√/√	√/√	√	√/√	√/√	√	x	√	√	√/√
SFTP	√/√	√/√	√	x/x	√/√	√	x	√	√	√/√
FTP	√/√	√/√	√	x/x	x/x	√	x	√	√	√/√

¹ Metadata lastModified:

• For Amazon S3, Amazon S3 Compatible Storage, Google Cloud Storage and Oracle Cloud Storage, lastModified applies to the bucket and the key but not to the virtual folder, and exists applies to the bucket and the key but not to the prefix or virtual folder.
• For Azure Blob storage, lastModified applies to the container and the blob but not to the virtual folder.

² Metadata structure and columnCount are not supported when getting metadata from Binary, JSON, or XML files.

³ Metadata exists: For Amazon S3, Amazon S3 Compatible Storage, Google Cloud Storage and Oracle Cloud Storage, exists applies to the bucket and the key but not to the prefix or virtual folder.

Note the following:

• When using Get Metadata activity against a folder, make sure you have LIST/EXECUTE permission to the given folder.

• Wildcard filter on folders/files is not supported for Get Metadata activity.

• modifiedDatetimeStart and modifiedDatetimeEnd filter set on connector:

  • These two properties are used to filter the child items when getting metadata from a folder. It does not apply when getting metadata from a file.
  • When such filter is used, the childItems in output includes only the files that are modified within the specified range but not folders.
  • To apply such filter, GetMetadata activity will enumerate all the files in the specified folder and check the modified time. Avoid pointing to a folder with a large number of files even if the expected qualified file count is small.

Relational database

Connector/Metadata	structure	columnCount	exists
Amazon RDS for SQL Server	√	√	√
Azure SQL Database	√	√	√
Azure SQL Managed Instance	√	√	√
Azure Synapse Analytics	√	√	√
SQL Server	√	√	√

Metadata options

You can specify the following metadata types in the Get Metadata activity field list to retrieve the corresponding information:

Metadata type	Description
itemName	Name of the file or folder.
itemType	Type of the file or folder. Returned value is File or Folder.
size	Size of the file, in bytes. Applicable only to files.
created	Created datetime of the file or folder.
lastModified	Last modified datetime of the file or folder.
childItems	List of subfolders and files in the given folder. Applicable only to folders. Returned value is a list of the name and type of each child item.
contentMD5	MD5 of the file. Applicable only to files.
structure	Data structure of the file or relational database table. Returned value is a list of column names and column types.
columnCount	Number of columns in the file or relational table.
exists	Whether a file, folder, or table exists. If exists is specified in the Get Metadata field list, the activity won't fail even if the file, folder, or table doesn't exist. Instead, exists: false is returned in the output.

Syntax

Get Metadata activity

{
    "name":"MyActivity",
    "type":"GetMetadata",
    "dependsOn":[

    ],
    "policy":{
        "timeout":"7.00:00:00",
        "retry":0,
        "retryIntervalInSeconds":30,
        "secureOutput":false,
        "secureInput":false
    },
    "userProperties":[

    ],
    "typeProperties":{
        "dataset":{
            "referenceName":"MyDataset",
            "type":"DatasetReference"
        },
        "fieldList":[
            "size",
            "lastModified",
            "structure"
        ],
        "storeSettings":{
            "type":"AzureBlobStorageReadSettings"
        },
        "formatSettings":{
            "type":"JsonReadSettings"
        }
    }
}

Dataset

{
    "name":"MyDataset",
    "properties":{
        "linkedServiceName":{
            "referenceName":"AzureStorageLinkedService",
            "type":"LinkedServiceReference"
        },
        "annotations":[

        ],
        "type":"Json",
        "typeProperties":{
            "location":{
                "type":"AzureBlobStorageLocation",
                "fileName":"file.json",
                "folderPath":"folder",
                "container":"container"
            }
        }
    }
}

Type properties

Currently, the Get Metadata activity can return the following types of metadata information:

Property	Description	Required
fieldList	The types of metadata information required. For details on supported metadata, see the Metadata options section of this article.	Yes
dataset	The reference dataset whose metadata is to be retrieved by the Get Metadata activity. See the Capabilities section for information on supported connectors. Refer to the specific connector topics for dataset syntax details.	Yes
formatSettings	Apply when using format type dataset.	No
storeSettings	Apply when using format type dataset.	No

Sample output

The Get Metadata results are shown in the activity output. Following are two samples showing extensive metadata options. To use the results in a subsequent activity, use this pattern: @{activity('MyGetMetadataActivity').output.itemName}.

Get a file's metadata

{
  "exists": true,
  "itemName": "test.csv",
  "itemType": "File",
  "size": 104857600,
  "lastModified": "2017-02-23T06:17:09Z",
  "created": "2017-02-23T06:17:09Z",
  "contentMD5": "cMauY+Kz5zDm3eWa9VpoyQ==",
  "structure": [
    {
        "name": "id",
        "type": "Int64"
    },
    {
        "name": "name",
        "type": "String"
    }
  ],
  "columnCount": 2
}

Get a folder's metadata

{
  "exists": true,
  "itemName": "testFolder",
  "itemType": "Folder",
  "lastModified": "2017-02-23T06:17:09Z",
  "created": "2017-02-23T06:17:09Z",
  "childItems": [
    {
      "name": "test.avro",
      "type": "File"
    },
    {
      "name": "folder hello",
      "type": "Folder"
    }
  ]
}

Related content

Learn about other supported control flow activities:

• Execute Pipeline activity
• ForEach activity
• Lookup activity
• Web activity