The references an external data type that cannot be mapped to a Data Flow task data type. The Data Flow task data type DT_WSTR will be used instead.

In SSIS when we will create task where data source is OLE DB source. Suppose it loads data from table tblSource:

CREATE TABLE tblSource(

    ID INT,

    Remarks SQL_VARIANT

)

We will get error message like:

The output "OLE DB Source Output" references an external data type that cannot be mapped to a Data Flow task data type. The Data Flow task data type DT_WSTR will be used instead.

The output column "" references an external data type that cannot be mapped to a Data Flow task data type. The Data Flow task data type DT_WSTR will be used instead.

Or will use OLE DB destination into the table tblSource, we will get error message like:

The input "OLE DB Destination Input" references an external data type that cannot be mapped to a Data Flow task data type. The Data Flow task data type DT_WSTR will be used instead.

Cause: SSIS doesn't support a column of data type SQL_VARIANT. So SSIS package will type case data of Remarks column into the DT_NEXT.

Solution:

Since it is warning message so if you want to continue it then, click on OK button.

Or you can also change the data type of Remarks column like VARCHAR(MAX), NVARCHAR(MAX) etc.