Read a Microsoft Fabric Lakehouse table

Provides the symmetric read counterpart to fabric_lakehouse_write_table(). It resolves a discovered Lakehouse object and table record, then delegates to the authenticated OneLake Delta reader. Use result = "arrow_stream" to keep a larger result out of R memory.

Usage

fabric_lakehouse_read_table(
  lakehouse,
  table,
  workspace = NULL,
  schema = NULL,
  columns = NULL,
  limit = NULL,
  version = NULL,
  result = c("tibble", "arrow_stream"),
  verbose = TRUE,
  tenant_id = Sys.getenv("FABRICQUERYR_TENANT_ID"),
  client_id = Sys.getenv("FABRICQUERYR_CLIENT_ID", unset =
    "04b07795-8ddb-461a-bbee-02f9e1bf7b46"),
  token = NULL,
  auth_args = list(),
  dfs_base = "https://onelake.dfs.fabric.microsoft.com"
)

Arguments

lakehouse

Lakehouse GUID, exact display name, or one Lakehouse object returned by fabric_lakehouses(). A discovered object is recommended because it carries its workspace ID and default schema.

table

Table name or one row returned by fabric_lakehouse_tables().

workspace

Workspace GUID, exact display name, or discovered workspace. Omit it when lakehouse is a discovered object containing workspaceId.

schema

Optional schema. A table record supplies its schema when this argument is omitted.

columns

Optional unique column names to project before collection.

limit

Optional non-negative maximum number of rows to return.

version

Optional non-negative Delta table version for time travel.

result

Return a "tibble" or a disk-backed, single-use "arrow_stream". Release a stream with stream[["release"]]() when using 'nanoarrow' directly, or close the 'arrow' reader that takes ownership of it

verbose

Whether to report authentication and read progress.

tenant_id

Entra tenant ID. Defaults to FABRICQUERYR_TENANT_ID.

client_id

Entra application ID. Defaults to FABRICQUERYR_CLIENT_ID, then the Azure CLI application ID.

token

Optional access token or audience-aware token-provider function.

auth_args

Additional sign-in options passed to AzureAuth::get_azure_token().

dfs_base

OneLake DFS service address. A private or regional endpoint on a discovered object is preferred when this argument is omitted.

Value

A tibble, or a disk-backed nanoarrow_array_stream when result = "arrow_stream". Explicit release deletes its temporary file.

References

OneLake table APIs for Delta

Connect to OneLake

Examples

if (FALSE) { # \dontrun{
# Discover both the Lakehouse and the table to read
workspace <- fabric_workspaces()[[1L]]
lakehouse <- fabric_lakehouses(workspace)[[1L]]
tables <- fabric_lakehouse_tables(lakehouse)
table <- tables[1L, ]

# Read the discovered table into a tibble
rows <- fabric_lakehouse_read_table(lakehouse, table)

# Stream selected columns when the full table may not fit in R memory
stream <- fabric_lakehouse_read_table(
  lakehouse,
  table,
  result = "arrow_stream"
)
reader <- arrow::as_record_batch_reader(stream)
rows <- reader$read_table()
reader$Close()
} # }