pentaho/pentaho-kettle · error · KettleDatabaseException

Unable to retrieve auto-increment of combi insert key : +…

Error message

Unable to retrieve auto-increment of combi insert key :  + meta.getTechnicalKeyField()

What it means

KettleDatabaseException wrapping a SQLException raised while calling keys.getLong(1)/getGeneratedKeys() in combiInsert — i.e. the JDBC driver itself threw while trying to retrieve the auto-increment value of the just-inserted combi (dimension) row, as opposed to simply getting no rows back.

Solutions

1. Inspect the wrapped SQLException cause; if it is 'feature not supported', switch tech key creation from auto-increment to sequence or table-maximum in the step settings.
2. Upgrade or correct the JDBC driver for your database.
3. Verify the database connection is still alive (network/firewall timeouts).
4. Avoid using getGeneratedKeys-requiring drivers with this step; use a sequence-based key.

Example fix

// before: 'use autoinc' checked with a driver lacking generated-keys support
// after: uncheck auto-increment and select 'use table maximum' / a named sequence
//        for the technical key in the CombinationLookup step dialog.

// verify driver supports generated keys before relying on autoinc
// DatabaseMetaData md = conn.getMetaData();
// log.info("Driver: " + md.getDatabaseProductName() + " " + md.getDriverVersion());

try { /* run */ } catch (KettleDatabaseException e) {
  if (e.getCause() instanceof SQLException) {
    log.error("Generated key retrieval failed: " + e.getCause().getMessage());
  }
}

When it happens

Trigger: After the combi insert, data.prepStatementInsert.getGeneratedKeys() or iterating the keys ResultSet throws SQLException; the catch block rethrows with the technical key field name and the SQL exception as cause.

Common situations: Driver does not support generated keys and throws instead of returning an empty set; connection lost between insert and key retrieval; statement closed or feature not implemented by the JDBC driver.

Understand the failure class

Background: "query failed", "%w: SQL error" — wrapped database query errors in Go libraries explained — this error's family across 3 libraries.

Related errors

• Unable to retrieve auto-increment of combi insert key : +…
• An error occurred executing SQL:
• An error occurred executing SQL:
• Couldn't execute SQL:
• Couldn't find any rows because of an error :

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/5458e88bc5480852. Report an issue: GitHub.

Appendix: source

Thrown at plugins/core/impl/src/main/java/org/pentaho/di/trans/steps/combinationlookup/CombinationLookup.java:634

      // INSERT NEW VALUE!
      data.db.setValues( data.insertRowMeta, insertRow, data.prepStatementInsert );

      debug = "Insert row";
      data.db.insertRow( data.prepStatementInsert );

      debug = "Retrieve key";
      if ( isAutoIncrement() && databaseMeta.supportsAutoGeneratedKeys() ) {
        ResultSet keys = null;
        try {
          keys = data.prepStatementInsert.getGeneratedKeys(); // 1 key
          if ( keys.next() ) {
            val_key = new Long( keys.getLong( 1 ) );
          } else {
            throw new KettleDatabaseException( "Unable to retrieve auto-increment of combi insert key : "
              + meta.getTechnicalKeyField() + ", no fields in resultset" );
          }
        } catch ( SQLException ex ) {
          throw new KettleDatabaseException( "Unable to retrieve auto-increment of combi insert key : "
            + meta.getTechnicalKeyField(), ex );
        } finally {
          try {
            if ( keys != null ) {
              keys.close();
            }
          } catch ( SQLException ex ) {
            throw new KettleDatabaseException( "Unable to retrieve auto-increment of combi insert key : "
              + meta.getTechnicalKeyField(), ex );
          }
        }
      }
    } catch ( Exception e ) {
      logError( Const.getStackTracker( e ) );
      throw new KettleDatabaseException( "Unexpected error in combination insert in part ["
        + debug + "] : " + e.toString(), e );
    }

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