Python Parameters Sent to the Database
The following table explains how Python objects passed to Cursor.execute() as parameters are formatted and sent to the driver/database.

Note on Large Text Data (varchar(max) / nvarchar(max)): Large text inputs passed as Python str are mapped to SQL_VARCHAR or SQL_WVARCHAR in the database, consistent with smaller text values. However, when the content size exceeds a certain threshold (e.g., beyond 8 KB for varchar or 4 KB for nvarchar), the driver may use streaming techniques during the execute() operation to efficiently transmit the data without buffering it entirely in memory. For more details on how this streaming is handled, see Streaming Support for Large Text Data.

Note on Description Column:

The "Description" column in the table is intended to provide a generic label for the type, and does not always reflect the exact SQL Server data type name. Please refer to the SQL Server column type for precise behavior and compatibility.

Note on SQL Server's timestamp and rowversion types

• In SQL Server, the timestamp type is a deprecated alias for rowversion, which is a binary type (binary(8)) used for version-stamping table rows. It does not represent a date or time value.
• The mapping table above may refer to "timestamp" as a generic type label, but this should not be confused with SQL Server's timestamp/rowversion type.
• At this time, rowversion/timestamp columns are not mapped to Python's datetime.datetime type; they should be treated as unsupported or as binary data.
• For actual date/time values, use SQL Server types such as datetime, datetime2, smalldatetime, or date.

Caution

If you need to use SQL Server's rowversion/timestamp, handle these columns as binary data in your Python code. They do not carry any date or time information.

SQL Values Received from the Database
The following table describes how database results are converted to Python objects.