Unsuccessful: alter table XXX drop constraint YYY in Hibernate/JPA/HSQLDB standalone

Question

I am trying to run some Hibernate/JPA examples using an in-memory HSQL DB. The error message I get is the following:

13:54:21,427 ERROR SchemaExport:425 - HH         


        

Answer 1

This solution worked for me, as opposed to the other solution that's given. Apparently mileages vary.

This was my exact error:

HHH000389: Unsuccessful: alter table ... drop constraint FK_g1uebn6mqk9qiaw45vnacmyo2 if exists
Table "..." not found; SQL statement: ...

This is my solution, overriding the H2 dialect:

package com.totaalsoftware.incidentmanager;

import org.hibernate.dialect.H2Dialect;

/**
 * Workaround.
 * 
 * @see https://hibernate.atlassian.net/browse/hhh-7002
 * 
 */
public class ImprovedH2Dialect extends H2Dialect {
    @Override
    public String getDropSequenceString(String sequenceName) {
        // Adding the "if exists" clause to avoid warnings
        return "drop sequence if exists " + sequenceName;
    }

    @Override
    public boolean dropConstraints() {
        // We don't need to drop constraints before dropping tables, that just
        // leads to error messages about missing tables when we don't have a
        // schema in the database
        return false;
    }
}