Apache Derby DB Error Code 42818 – Comparisons between ‘‘ and ‘‘ are not supported.

In this blog post, let’s learn about the error message “42818- Comparisons between ‘‘ and ‘‘ are not supported.” in Apache Derby Database and the description of the error.

Error Message

42818- Comparisons between ‘‘ and ‘‘ are not supported.

Error Details

Comparisons between ‘‘ and ‘‘ are not supported. Types must be comparable. String types must also have matching collation. If collation does not match, a possible solution is to cast operands to force them to the default collation (e.g. SELECT tablename FROM sys.systables WHERE CAST(tablename AS VARCHAR(128)) = ‘T1’)