pentaho/pentaho-kettle · error · KettleStepException

Please set a value for the missing field(s) type.

Error message

Please set a value for the missing field(s) type.

What it means

In the same putRow() validation loop, a ValueMetaInterface whose getType() <= 0 (undefined/missing type) causes KettleStepException 'Please set a value for the missing field(s) type.' Each outgoing field must have a concrete Kettle data type.

Solutions

  1. Assign a concrete type, e.g. vmi.setValueType(ValueMetaInterface.TYPE_STRING), before putRow.
  2. Construct value metas with an explicit type: new ValueMetaString("field") instead of a typeless base.
  3. Set allowEmptyFieldNamesAndTypes(true) only if untyped fields must be tolerated.
  4. Use a 'Select Values'/metadata step upstream to force types on unspecified fields.

Example fix

// before
ValueMetaInterface vmi = new ValueMetaBase("field"); // type 0
// after
ValueMetaInterface vmi = new ValueMetaString("field");
Defensive patterns

Strategy: validation

Validate before calling

for (ValueMetaInterface vmi : rowMeta.getValueMetaList()) {
  if (vmi.getType() <= 0) vmi.setValueType(ValueMetaInterface.TYPE_STRING); // or throw
}

Try / catch

try { putRow(rowMeta, row); }
catch (KettleStepException e) { if (e.getMessage().contains("missing field(s) type")) { forceTypes(rowMeta); putRow(rowMeta, row); } else throw e; }

Prevention

When it happens

Trigger: putRow() called with a row meta containing a value meta constructed without a type (type 0 / TYPE_NONE), e.g. new ValueMetaBase("field") with no type assigned, or metadata copied from an undefined source column.

Common situations: Scripting/UDJC steps that create ValueMeta objects but never set the type; 'unspecified' columns passed through from Get Files / Excel stages; merge-join producing fields of unknown type.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/7bfe7ff4afd728de. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/step/BaseStep.java:1257

  /**
   * putRow is used to copy a row, to the alternate rowset(s) This should get priority over everything else!
   * (synchronized) If distribute is true, a row is copied only once to the output rowsets, otherwise copies are sent to
   * each rowset!
   *
   * @param row The row to put to the destination rowset(s).
   * @throws KettleStepException
   */
  @Override
  public void putRow( RowMetaInterface rowMeta, Object[] row ) throws KettleStepException {
    if ( rowMeta != null ) {
      if ( !allowEmptyFieldNamesAndTypes ) {
        // check row meta for empty field name (BACKLOG-18004)
        for ( ValueMetaInterface vmi : rowMeta.getValueMetaList() ) {
          if ( StringUtils.isBlank( vmi.getName() ) ) {
            throw new KettleStepException( "Please set a field name for all field(s) that have 'null'." );
          }
          if ( vmi.getType() <= 0 ) {
            throw new KettleStepException( "Please set a value for the missing field(s) type." );
          }
        }
      }
    }
    getRowHandler().putRow( rowMeta, row );
  }

  private void handlePutRow( RowMetaInterface rowMeta, Object[] row ) throws KettleStepException {
    // Are we pausing the step? If so, stall forever...
    //
    while ( paused.get() && !stopped.get() ) {
      try {
        Thread.sleep( 1 );
      } catch ( InterruptedException e ) {
        throw new KettleStepException( e );
      }
    }

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