Union Query Long Datatypes and a "Placeholder" Corresponding Value

Oracle server 8.1.7.4.0

I'm dealing with an application over which I have no real control to be able to change table structure other than to add my own columns. I am trying to create a union query of the sort:

SELECT c1, c2 FROM ....
UNION ALL
SELECT c1, c2 FROM ....

When c2 data type is long in both tables I am fine. However, I have one case where c2 is a long data type in one table and there is nothing corresponding in the second table (it does not have a long datatype column). Is there a way to handle this?

I've tried:

SELECT c1, c2 FROM ....
UNION ALL
SELECT c1, '' c2 FROM ....

in an attempt to have '' stand in for the long data type, ie, what I call a "Placeholder" corresponding value in my title. This results in ora 01790 expression must have same datatype as corresponding expression.

Is there a way to handle this? I could add a "dummy" long into the second table, but this would be a last resort.

Thanks in advance.

-- 
Tim   http://www.ucs.mun.ca/~tmarshal/
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