You are building a database in an Azure Synapse Analytics serverless SQL pool.

Box 1: CREATE EXTERNAL TABLE

An external table points to data located in Hadoop, Azure Storage blob, or Azure Data Lake Storage. External tables are used to read data from files or write data to files in Azure Storage. With Synapse SQL, you can use external tables to read external data using dedicated SQL pool or serverless SQL pool.

Syntax:

CREATE EXTERNAL TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name }

( [ ,...n ] )

WITH (

LOCATION = 'folder_or_filepath',

DATA_SOURCE = external_data_source_name,

FILE_FORMAT = external_file_format_name

Box 2. OPENROWSET

When using serverless SQL pool, CETAS is used to create an external table and export query results to Azure Storage Blob or Azure Data Lake Storage Gen2.

Example:

AS

SELECT decennialTime, stateName, SUM(population) AS population

FROM

OPENROWSET(BULK 'https://azureopendatastorage.blob.core.windows.net/censusdatacontainer/release/us_population_county/year=*/*.parquet ',

FORMAT='PARQUET') AS [r]

GROUP BY decennialTime, stateName

GO