Oracle Solution for Error ora-01754

ORA-01754: a table may contain only one column of type LONG

What triggered the Error:

An attempt was made to add a LONG column to a table which already had a LONG column. Note that even if the LONG column currently in the table has already been marked unused, another LONG column may not be added until the unused columns are dropped.

What should we do to fix it:

Remove the LONG column currently in the table by using the ALTER TABLE command.