IMPORT: Add support for importing a NULL data type from JDBC

Detail name	Value
Changelog Number	17935
Type	Improvement
Status	Resolved
Fix Versions	Exasol 8.24.0, Exasol 7.1.25
Resolution Date	2023-12-04

Background

Currently, when using IMPORT FROM JDBC, data cannot be imported if the column in the source has a NULL data type.

Note: This improvement only affects columns with type NULL (instead of CHAR, DECIMAL, etc.). NULL values can always be imported.

Improvement

Data can now be imported from a column with a NULL data type.