Read multiple CSV files by extension

Reads only CSV files matching the given extension(s) from a folder. Use FilterFilesByExtension to limit which files are read (e.g. txt for .txt files).

Standard SQL query example

This is the base query accepted by the connector. To execute it in SQL Server, you have to pass it to the Data Gateway via a Linked Server. See how to accomplish this using the examples below.

SELECT * FROM read_csv_files_from_folder
WITH (FilterFilesByExtension='txt')

Using OPENQUERY in SQL Server

SELECT * FROM OPENQUERY([LS_TO_DROPBOX_IN_GATEWAY], 'SELECT * FROM read_csv_files_from_folder
WITH (FilterFilesByExtension=''txt'')')

Using EXEC in SQL Server (handling larger SQL text)

The major drawback of OPENQUERY is its inability to incorporate variables within SQL statements. This often leads to the use of cumbersome dynamic SQL (with numerous ticks and escape characters).

Fortunately, starting with SQL 2005 and onwards, you can utilize the EXEC (your_sql) AT [LS_TO_DROPBOX_IN_GATEWAY] syntax.

DECLARE @MyQuery NVARCHAR(MAX) = 'SELECT * FROM read_csv_files_from_folder
WITH (FilterFilesByExtension=''txt'')'
EXEC (@MyQuery) AT [LS_TO_DROPBOX_IN_GATEWAY]