to_lob converts LONG or LONG RAW values in the column long_column to LOB values. You can apply this function only to a LONG or LONG RAW column, and only in the SELECT list of a subquery in an INSERT statement.

Before using this function, you must create a LOB column to receive the converted LONG values. To convert LONGs, create a CLOB column. To convert LONG RAWs, create a BLOB column.