greenrobot/greenDAO · error · DaoException

Unsupported operation

Error message

Unsupported operation: ${operation.type}

What it means

executeOperation switches over AsyncOperation.Type to dispatch to the right DAO/session method. The default branch throws DaoException when the operation's type has no handler — i.e. an unknown or unsupported operation type reached the executor, typically from an older/newer greendao mismatch or custom code crafting operations.

Solutions

1. Verify all greendao artifacts come from a single consistent version; remove duplicate/stale DaoCore jars from the classpath.
2. Log operation.type to identify which operation kind is unsupported, and upgrade greendao to a version that handles it.
3. Avoid constructing AsyncOperation instances manually with arbitrary types; use the AsyncSession API methods.
4. After an AsyncSession.clear() or upgrade, clean/rebuild the project to avoid stale compiled classes.

Example fix

// build.gradle: before
def versions = [greendao: '3.2.2', greendaoApi: '3.1.0'] // mismatched
// after
def versions = [greendao: '3.3.0', greendaoApi: '3.3.0'] // aligned

// ensure a single greendao version on the classpath
Set<String> versions = classpathArtifactsMatching("org.greenrobot:greendao");
if (versions.size() != 1) throw new IllegalStateException("mixed greendao versions: " + versions);

try {
    asyncSession.insert(entity);
} catch (DaoException e) {
    if (e.getMessage().startsWith("Unsupported operation:")) {
        log.severe("greendao version mismatch or unhandled op type");
    }
}

When it happens

Trigger: An AsyncOperation whose type is not one of the handled cases (e.g. a type added in a newer greendao release executed by an older core, or custom AsyncOperation construction with an unhandled type).

Common situations: Mixed greendao/greendao-api versions on the classpath (duplicate jars), shading/repackaging that splits classes, or framework code generating operation types this build's executor doesn't know.

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

• This operation did not yet complete
• Expected unique result, but count was
• Cannot delete entity, key is null
• Entity does not exist in the database anymore
• Cannot update entity without key - was it inserted before?

AI-assisted analysis of greenrobot/greenDAO@0bbb338e17 (2026-09-08). Data as JSON: /api/errors/3d6fca3357c53793. Report an issue: GitHub.

Appendix: source

Thrown at DaoCore/src/main/java/org/greenrobot/greendao/async/AsyncOperationExecutor.java:335

                    operation.dao.deleteByKey(operation.parameter);
                    break;
                case DeleteAll:
                    operation.dao.deleteAll();
                    break;
                case Load:
                    operation.result = operation.dao.load(operation.parameter);
                    break;
                case LoadAll:
                    operation.result = operation.dao.loadAll();
                    break;
                case Count:
                    operation.result = operation.dao.count();
                    break;
                case Refresh:
                    operation.dao.refresh(operation.parameter);
                    break;
                default:
                    throw new DaoException("Unsupported operation: " + operation.type);
            }
        } catch (Throwable th) {
            operation.throwable = th;
        }
        operation.timeCompleted = System.currentTimeMillis();
        // Do not set it to completed here because it might be a merged TX
    }

    private void executeTransactionRunnable(AsyncOperation operation) {
        Database db = operation.getDatabase();
        db.beginTransaction();
        try {
            ((Runnable) operation.parameter).run();
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }
    }

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