Oracle Error PLS-00620: type mismatch found at ‘string’ among operands in a COALESCE expression

Oracle Error Message

PLS-00620: type mismatch found at ‘string’ among operands in a COALESCE expression

Reason for the Error

In a COALESCE expression, the operands do not match in datatype, and it is unclear which implicit conversion is required to correct the mismatch.

Solution

Change the operands so that their datatypes match. Consider using datatype conversion functions in the operands.