hibernate/hibernate-orm · error · SchemaManagementException

Schema validation: missing sequence

Error message

Schema validation: missing sequence [%s]

What it means

Sequence validation: the mapping defines an ID sequence (@SequenceGenerator / <sequence/>) but no SequenceInformation was found in JDBC metadata for that name - the database has no such sequence. Validation aborts because the ID generator would fail at runtime anyway, so Hibernate refuses to start.

Solutions

1. Create the missing sequence with the mapped name: CREATE SEQUENCE order_seq START WITH 1 INCREMENT BY <allocationSize>;
2. Align sequenceName (and schema qualification) in @SequenceGenerator with the sequence that actually exists.
3. Ensure migrations include sequence DDL and run before validation in every environment.
4. On databases without sequences, switch the generator to IDENTITY/TABLE (or a dialect-appropriate strategy).

Example fix

-- before: entity expects order_seq (allocationSize 50) but the database has no such sequence
-- @SequenceGenerator(name = "order_seq", sequenceName = "order_seq", allocationSize = 50)

-- after: create it with a matching increment
CREATE SEQUENCE order_seq START WITH 1 INCREMENT BY 50;

// Before validate, confirm every mapped sequence exists (and its increment matches)
try (Connection c = dataSource.getConnection()) {
    DatabaseMetaData md = c.getMetaData();
    try (ResultSet rs = md.getTables(null, null, "order_seq", new String[]{"SEQUENCE"})) {
        // portable enough for a smoke check on most drivers; alternatively query information_schema.sequences
        if (!rs.next()) {
            throw new IllegalStateException("order_seq missing - create it before validate");
        }
    }
}

try {
    new SchemaValidator().validate(metadata, serviceRegistry);
} catch (SchemaManagementException e) {
    if (e.getMessage() != null && e.getMessage().contains("missing sequence")) {
        // create the sequence with matching name/schema/increment, or align sequenceName in the generator
    }
    throw e;
}

When it happens

Trigger: hibernate.hbm2ddl.auto=validate with @GeneratedValue(strategy = SEQUENCE) plus a generator whose sequenceName has no CREATE SEQUENCE counterpart in the database: migrations created tables but not sequences; the sequence lives in another schema (default_schema/qualification mismatch); the sequence name differs in case/quoting; the target database does not support sequences at all (MySQL before sequence support), so a sequence strategy cannot work.

Common situations: Fresh environments where only table DDL was migrated; switching from IDENTITY to SEQUENCE generators without shipping sequence DDL; PostgreSQL schema-qualified names (public.order_seq vs order_seq); H2 vs Postgres name handling; running validate before the migration step in CI.

Related errors

• Schema validation: sequence
• Could not fetch the SequenceInformation from the database
• dialect does not support sequences
• Error performing isolated work
• Index mismatch - ` ` on table

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/cf980d0995b894be. Report an issue: GitHub.

Appendix: source

Thrown at hibernate-core/src/main/java/org/hibernate/tool/schema/internal/AbstractSchemaValidator.java:311

				}
			}

			if ( !matches ) {
				throw new SchemaManagementException(
						String.format(
								ROOT,
								"Unique-key mismatch - `%s` on table `%s`",
								name.render( dialect ),
								tableInformation.getName().render()
						)
				);
			}
		} );
	}

	protected void validateSequence(Sequence sequence, SequenceInformation sequenceInformation) {
		if ( sequenceInformation == null ) {
			throw new SchemaManagementException(
					String.format( "Schema validation: missing sequence [%s]", sequence.getName() )
			);
		}

		final Number incrementValue = sequenceInformation.getIncrementValue();
		if ( incrementValue != null && incrementValue.intValue() > 0
				&& sequence.getIncrementSize() != incrementValue.intValue() ) {
			throw new SchemaManagementException(
					String.format(
							"Schema validation: sequence [%s] defined inconsistent increment-size; found [%s] but expecting [%s]",
							sequence.getName(),
							incrementValue,
							sequence.getIncrementSize()
					)
			);
		}
	}
}

View on GitHub (pinned to fad1729dce)