How to fix the Oracle error PLS-01913: : instance must of be of type ‘string’ or one of its subtypes?

In this post, you’ll learn more about the Oracle ErrorPLS-01913: : instance must of be of type ‘string’ or one of its subtypes with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

PLS-01913: : instance must of be of type ‘string’ or one of its subtypes

Reason for the Error PLS-01913: : instance must of be of type ‘string’ or one of its subtypes

The run-time type of the instance is the not declared type or one of its subtypes. e.g. TREAT(supertype AS subtype) fails.

How to fix the Error PLS-01913: : instance must of be of type ‘string’ or one of its subtypes ?

You can fix this error in Oracle by following the below steps

Catch the exception.