apache/seatunnel · error · JdbcConnectorException

UNSUPPORTED_DATA_TYPE

UNSUPPORTED_DATA_TYPE

Error message

Unexpected value: 

What it means

setValueToStatementByDataType only implements JDBC parameter binding for scalar SeaTunnel types; MAP, ROW types (and any default/unknown case) hit the switch default and throw UNSUPPORTED_DATA_TYPE with 'Unexpected value: <type>'. The JDBC sink cannot flatten nested structures into a single SQL column via this converter path.

Source

Thrown at seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/converter/AbstractJdbcRowConverter.java:353

                Object[] array = (Object[]) value;
                if (array == null) {
                    statement.setNull(statementIndex, java.sql.Types.ARRAY);
                    break;
                }
                if (SqlType.TINYINT.equals(elementType.getSqlType())) {
                    Short[] shortArray = new Short[array.length];
                    for (int i = 0; i < array.length; i++) {
                        shortArray[i] = Short.valueOf(array[i].toString());
                    }
                    statement.setObject(statementIndex, shortArray);
                } else {
                    statement.setObject(statementIndex, array);
                }
                break;
            case MAP:
            case ROW:
            default:
                throw new JdbcConnectorException(
                        CommonErrorCodeDeprecated.UNSUPPORTED_DATA_TYPE,
                        "Unexpected value: " + seaTunnelDataType);
        }
    }

    protected void writeTime(PreparedStatement statement, int index, LocalTime time)
            throws SQLException {
        statement.setTime(index, java.sql.Time.valueOf(time));
    }
}

View on GitHub (pinned to cf67b549a7)

Solutions

1. Flatten MAP/ROW fields into scalar columns before the JDBC sink (use a Transform to extract fields)
2. If supported for your dialect, enable dialect-specific nested-type handling or upgrade SeaTunnel for broader type support
3. Change the sink table/schema so nested data is serialized to a JSON string column first
4. Check AbstractJdbcRowConverter's supported cases and pick a sink/converter that supports your type

Example fix

// before
field { name = "addr" type = ROW { city STRING zip STRING } }   # goes to JDBC sink
// after
fields: addr_city STRING, addr_zip STRING  (flatten with a Transform before sink)

for (SeaTunnelDataType t : rowType.getFieldTypes()) {
    if (t instanceof MapType || t instanceof RowType || t instanceof ArrayType) {
        throw new IllegalArgumentException("JDBC sink cannot bind nested type: " + t);
    }
}

boolean isFlatScalar(SeaTunnelDataType<?> t) {
    return !(t instanceof MapType) && !(t instanceof RowType) && !(t instanceof ArrayType);
}

try {
    converter.toExternal(row, statement);
} catch (JdbcConnectorException e) {
    if (e.getErrorCode() == CommonErrorCodeDeprecated.UNSUPPORTED_DATA_TYPE) {
        LOG.error("Flatten nested field before JDBC sink; offending type: {}", e.getMessage());
    }
    throw e;
}

When it happens

Trigger: toExternal() is called on a row whose schema contains a MAP or ROW field (or an otherwise unmapped data type), and the converter attempts to set that field on the PreparedStatement.

Common situations: Upstream source (e.g. JSON, MongoDB, Kafka) emits nested objects/arrays that flow unmodified into a JDBC sink; schema not flattened before writing to relational storage; missing dialect support for array/struct types for your database.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• COMMON-19
• COMMON-19
• CONNECT_FAILED
• UNSUPPORTED_DATA_TYPE
• CONNECT_DATABASE_FAILED

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/c2cc97f5549ff0a0. Report an issue: GitHub.