What causes " mapping needs to specify 2 or more columns" in hibernate/hibernate-orm?

Map two or more columns: the first is the discriminator matching meta-type values, e.g. , followed by the fk, e.g.

hibernate/hibernate-orm · error · MappingException

<any name="%s" /> mapping needs to specify 2 or more columns

Error message

<any name="%s" /> mapping needs to specify 2 or more columns

What it means

<any/> maps a polymorphic entity reference on a singular attribute and needs at least two relational values: column #1 is the discriminator (resolved through meta-type to an entity name) and the remaining column(s) are the foreign key. SingularAttributeSourceAnyImpl aborts bootstrap when fewer than two column definitions are supplied.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/SingularAttributeSourceAnyImpl.java:90

					@Override
					public String getSourceName() {
						return jaxbAnyMapping.getName();
					}

					@Override
					public List getColumnOrFormulaElements() {
						return jaxbAnyMapping.getColumn();
					}
				}
		);

		// the list of relational values should contain 2 or more values:
		//		* the first represents the discriminator
		//		* the rest represent the fk

		if ( relationalValueSources.size() < 2 ) {
			throw new MappingException(
					String.format(
							Locale.ENGLISH,
							"<any name=\"%s\" /> mapping needs to specify 2 or more columns",
							jaxbAnyMapping.getName()
					),
					origin()
			);
		}

		this.discriminatorSource = new AnyDiscriminatorSource() {
			private final HibernateTypeSource typeSource = new HibernateTypeSourceImpl( jaxbAnyMapping.getMetaType() );
			private final RelationalValueSource relationalValueSource = relationalValueSources.get( 0 );
			private final Map<String,String> valueMappings = new HashMap<>();
			{
				for ( JaxbHbmAnyValueMappingType valueMapping : jaxbAnyMapping.getMetaValue() ) {
					valueMappings.put(
							valueMapping.getValue(),
							sourceMappingDocument.qualifyClassName( valueMapping.getClazz() )

View on GitHub (pinned to fad1729dce)

Solutions

Map two or more columns: the first is the discriminator matching meta-type values, e.g. <column name='owner_type'/>, followed by the fk, e.g. <column name='owner_id'/>
Add <meta-value .../> entries where discriminator values differ from entity names, and verify meta-type/id-type match the column contents
If the schema has only one column, <any> cannot work - use a plain association or add the discriminator column first

Example fix

// before
<any name='owner' meta-type='string' id-type='long'>
    <column name='owner_id'/>
</any>

// after
<any name='owner' meta-type='string' id-type='long'>
    <column name='owner_type'/>
    <column name='owner_id'/>
</any>

Defensive patterns

Strategy: validation

Validate before calling

// Pre-flight: every <any> must declare >= 2 columns
var any = (org.w3c.dom.Element) doc.getElementsByTagName("any").item(0);
int n = any.getElementsByTagName("column").getLength();
if (n < 2)
    throw new IllegalStateException("<any name='" + any.getAttribute("name")
            + "'> needs discriminator + fk columns, found " + n);

Try / catch

catch (org.hibernate.boot.MappingException e) at Metadata build: the message names the <any> attribute - add the discriminator column first and the fk column(s) after it

Prevention

When mapping interface-typed associations, always provision a discriminator column plus fk column(s)
First column = discriminator (meta-type), remaining columns = fk - keep the order
Prefer annotation-based @Any with explicit @Column defs where the two-column need is obvious

When it happens

Trigger: An <any name='owner' meta-type='string' id-type='long'> mapping with zero or one <column> children - e.g. only <column name='owner_id'/> - declared on an entity or component mapping.

Common situations: Modeling an interface-typed association and forgetting the discriminator column; converting a <many-to-one> to <any> without altering the table; writing hbm equivalents of @Any annotations and missing one @Column.

Related errors

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/59b44b69e6234c10. Report an issue: GitHub.