AzureStorage.DataLakeContents

Accessing Data

Returns the content of a file from Azure Data Lake Storage as binary.

Syntax

AzureStorage.DataLakeContents(url as text, optional options as nullable record) as binary

Parameters

Name	Type	Required	Description
`url`	`text`	Yes	The full URL of the file in Azure Data Lake Storage Gen2 (e.g., "https://myaccount.dfs.core.windows.net/myfilesystem/path/file.csv").
`options`	`record`	No	An optional record to control download behavior. Supported fields include BlockSize, RequestSize, and ConcurrentRequests.

Return Value

binary — The binary content of the specified file from an Azure Data Lake Storage filesystem.

Remarks

AzureStorage.DataLakeContents downloads a single file from Azure Data Lake Storage Gen2 and returns its content as a binary value. This is the Data Lake equivalent of AzureStorage.BlobContents and is designed for ADLS Gen2 endpoints that use the dfs.core.windows.net domain. The binary result is typically passed to a parser function such as Csv.Document, Json.Document, or Excel.Workbook.

Key options (passed in the options record):

BlockSize (number) -- the number of bytes to read before waiting on the data consumer. Defaults to 4 MB.
RequestSize (number) -- the number of bytes to try to read in a single HTTP request to the server. Defaults to 4 MB.
ConcurrentRequests (number) -- the number of requests to make in parallel for faster downloads. Memory required is approximately ConcurrentRequests multiplied by RequestSize. Defaults to 16.

Authentication: Supports Account Key, Shared Access Signature (SAS), Microsoft Account (Azure AD / Entra ID), and service principal authentication. Configure the credential type in the data source credentials dialog. Do not embed keys or tokens in the M query.

Query folding: Not applicable. This function downloads the entire file as a single binary stream. Any filtering or transformation is performed locally after the data is downloaded and parsed.

Platform availability: Available across all Power Query environments including Power BI Desktop, Power BI Service, Excel Desktop, Excel Online, Dataflows, and Fabric Notebooks. No gateway is required for cloud-to-cloud access.

Examples

Example 1: Download a CSV file from Azure Data Lake Storage

let
    Source = AzureStorage.DataLakeContents("https://myaccount.dfs.core.windows.net/myfilesystem/data/sales.csv"),
    Parsed = Csv.Document(Source, [Delimiter = ",", Encoding = TextEncoding.Utf8]),
    Promoted = Table.PromoteHeaders(Parsed, [PromoteAllScalars = true])
in
    Promoted

Example 2: Download a JSON file with custom request settings

let
    Source = AzureStorage.DataLakeContents(
        "https://myaccount.dfs.core.windows.net/myfilesystem/data/config.json",
        [ConcurrentRequests = 8, RequestSize = 2097152]
    ),
    Parsed = Json.Document(Source)
in
    Parsed

Example 3: Download an Excel workbook from Data Lake Storage

let
    Source = AzureStorage.DataLakeContents("https://myaccount.dfs.core.windows.net/myfilesystem/reports/monthly.xlsx"),
    Workbook = Excel.Workbook(Source, true),
    Sheet1 = Workbook{[Item = "Sheet", Name = "Sheet1"]}[Data]
in
    Sheet1

Compatibility

✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks