hibernate/hibernate-orm · error · IllegalArgumentException

No singular attribute named '{}' and of type '{}' in type '{

Error message

No singular attribute named '{}' and of type '{}' in type '{}'

What it means

getDeclaredSingularAttribute(name, Class) failed because either no singular attribute with that name exists on the type, or one exists but its Java type does not match the requested Class (hasMatchingReturnType). The message includes the requested type only when non-null, so 'of type null' means the lookup by name itself failed.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/metamodel/model/domain/internal/AbstractManagedType.java:332

	@Override
	@Nullable
	public SqmSingularPersistentAttribute<J, ?> findDeclaredSingularAttribute(@Nonnull String name) {
		return declaredSingularAttributes.get( name );
	}

	@Override
	@Nonnull
	public <Y> SingularPersistentAttribute<J, Y> getDeclaredSingularAttribute(@Nonnull String name, @Nonnull Class<Y> javaType) {
		return checkTypeForSingleAttribute( findDeclaredSingularAttribute( name ), name, javaType );
	}

	private <K,Y> SqmSingularPersistentAttribute<K,Y> checkTypeForSingleAttribute(
			SqmSingularPersistentAttribute<K,?> attribute,
			String name,
			Class<Y> javaType) {
		if ( attribute == null || !hasMatchingReturnType( attribute, javaType ) ) {
			throw new IllegalArgumentException(
					"No singular attribute named '" + name
					+ ( javaType != null ? "' and of type '" + javaType.getName() : "" )
					+ "' in type '" + hibernateTypeName + "'"
			);
		}
		else {
			@SuppressWarnings("unchecked")
			final SqmSingularPersistentAttribute<K, Y> narrowed =
					(SqmSingularPersistentAttribute<K, Y>) attribute;
			return narrowed;
		}
	}

	private <T, Y> boolean hasMatchingReturnType(SingularAttribute<T, ?> attribute, Class<Y> javaType) {
		return javaType == null
			|| attribute.getJavaType().equals( javaType )
			|| isPrimitiveVariant( attribute, javaType );
	}

View on GitHub (pinned to fad1729dce)

Solutions

1. Verify the attribute exists and its exact Java type: findDeclaredSingularAttribute(name) then inspect getJavaType()
2. Use the untyped overload or CollectionAttribute APIs for plural attributes
3. Use getId-style matching with the actual type from attribute.getJavaType() rather than a hard-coded class

Example fix

// before
var a = productType.getDeclaredSingularAttribute("tags", String.class); // tags is a Set -> throws

// after
var a = productType.getDeclaredPluralAttribute... // if plural
// or for singular: type matches attribute.getJavaType()

// Look up untyped first, then verify the Java type
var attr = managedType.getDeclaredSingularAttribute(name); // untyped, null-safe? throws if missing
// safer:
for (Attribute<?,?> a : managedType.getAttributes()) {
    if (a.getName().equals(name) && a instanceof SingularAttribute<?,?> sa
            && expected.isAssignableFrom(sa.getJavaType())) { /* safe to use */ }
}

static boolean isSingularOf(ManagedType<?> type, String name, Class<?> expected) {
    for (Attribute<?,?> a : type.getAttributes()) {
        if (a.getName().equals(name)
                && a instanceof SingularAttribute<?,?> sa
                && expected.isAssignableFrom(sa.getAttributeJavaType())) return true;
    }
    return false;
}

try {
    return type.getDeclaredSingularAttribute(name, cls);
} catch (IllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("No singular attribute named")) {
        // name wrong, or type mismatch, or attribute is plural
        throw new NoSuchFieldException(name + " on " + type.getTypeName());
    }
    throw e;
}

When it happens

Trigger: Calling getDeclaredSingularAttribute("name", Integer.class) when 'name' is a String or is a plural/collection attribute; requesting an inherited attribute through the declared variant; misspelled name.

Common situations: Refactoring an attribute's type (e.g. Integer -> Long) while callers still request the old wrapper. Attempting to read a List/Set/Map attribute through the singular API. Base-class attributes with the declared variant.

Related errors

• Attribute [%s#%s : %s] not castable to requested type [%s]
• Unable to locate %s with the given name [%s] on this Managed
• No plural attribute named '{}' and of element type '{}' in t
• ${name} is not a CollectionAttribute: ${attributeClass}
• ${name} is not a SetAttribute: ${attributeClass}

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/12f13ce37b0ca2f3. Report an issue: GitHub.