Oracle Error PLS-00644: character set mismatch found at ‘string’ among result expressions in a CASE expression

Oracle Error Message

PLS-00644: character set mismatch found at ‘string’ among result expressions in a CASE expression

Reason for the Error

In a CASE expression, the result expressions do not match in character set, and it is unclear which implicit conversion is required to correct the mismatch.

Solution

Change the result expressions so that their character sets match.