pentaho/pentaho-kettle · error · KettleStepException

TableCompareMeta.Exception.NrErrorsLeftJoinFieldNotSpecified

Error message

TableCompareMeta.Exception.NrErrorsLeftJoinFieldNotSpecified

What it means

Fourth check in TableCompareMeta.getFields(): the 'nr errors left join' output field (nrErrorsLeftJoinField) is not specified. The step reports left-join mismatch counts and needs this output field name.

Solutions

Set the 'nr errors left join field' in the step dialog (e.g. 'nr_errors_left').
In code, call meta.setNrErrorsLeftJoinField("nr_errors_left").
Fix the .ktr XML <nr_errors_left_join_field> tag.

Example fix

// before
meta.setNrRecordsCompareField( "nr_records_compare" );
// after
meta.setNrRecordsCompareField( "nr_records_compare" );
meta.setNrErrorsLeftJoinField( "nr_errors_left" );

Defensive patterns

Strategy: validation

Validate before calling

if ( meta.getNrErrorsLeftJoinField() == null || meta.getNrErrorsLeftJoinField().isEmpty() ) {
  meta.setNrErrorsLeftJoinField( "nr_errors_left" );
}

Try / catch

try {
  meta.getFields( ... );
} catch ( KettleStepException e ) {
  if ( e.getMessage().contains( "NrErrorsLeftJoinFieldNotSpecified" ) ) {
    meta.setNrErrorsLeftJoinField( "nr_errors_left" );
  }
}

Prevention

Configure join-error fields together with the count fields, never separately.
Keep a canonical TableCompareMeta factory in code for generated transformations.
Review .ktr diffs for dropped tags after merges.

When it happens

Trigger: getFields(...) invoked with nrErrorsLeftJoinField null/empty — thrown at TableCompareMeta.java:385 after the first three checks pass.

Common situations: Programmatic construction setting only the main count fields; hand-edited .ktr XML; generated transformations from templates predating the join-error outputs.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/857d8e7f242f685a. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/tablecompare/TableCompareMeta.java:385

  @Override
  public void getFields( Bowl bowl, RowMetaInterface inputRowMeta, String origin, RowMetaInterface[] info,
    StepMeta nextStep, VariableSpace space, Repository repository, IMetaStore metaStore ) throws KettleStepException {

    if ( Utils.isEmpty( nrErrorsField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrErrorsFieldIsNotSpecified" ) );
    }
    if ( Utils.isEmpty( nrRecordsReferenceField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrRecordsReferenceFieldNotSpecified" ) );
    }
    if ( Utils.isEmpty( nrRecordsCompareField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrRecordsCompareFieldNotSpecified" ) );
    }
    if ( Utils.isEmpty( nrErrorsLeftJoinField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrErrorsLeftJoinFieldNotSpecified" ) );
    }
    if ( Utils.isEmpty( nrErrorsInnerJoinField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrErrorsInnerJoinFieldNotSpecified" ) );
    }
    if ( Utils.isEmpty( nrErrorsRightJoinField ) ) {
      throw new KettleStepException( BaseMessages.getString(
        PKG, "TableCompareMeta.Exception.NrErrorsRightJoinFieldNotSpecified" ) );
    }

    ValueMetaInterface nrErrorsValueMeta = new ValueMetaInteger( nrErrorsField );
    nrErrorsValueMeta.setLength( 9 );
    nrErrorsValueMeta.setOrigin( origin );
    inputRowMeta.addValueMeta( nrErrorsValueMeta );

    ValueMetaInterface nrRecordsReference =
      new ValueMetaInteger( nrRecordsReferenceField );

View on GitHub (pinned to f3058517a1)