pentaho/pentaho-kettle · error · KettleDatabaseException

error opening resultset for query: " + sql

Error message

error opening resultset for query: " + sql

What it means

Database.openQuery() could not open a JDBC ResultSet for the given SQL string. The method returns a RowMetaAndData on success, but if the query produced no row or the execution failed, Kettle wraps the failure in a KettleDatabaseException that includes the offending SQL so the developer can see exactly which statement broke.

Solutions

1. Log or print the exact 'sql' string in the message and run it directly against the database to see the underlying driver error
2. Verify the table and column names exist in the connected database/schema
3. Check the database connection settings and test with Database.connect() before querying
4. Enable Kettle debug logging to capture the driver-level exception that preceded this throw

Example fix

// before
RowMetaAndData r = db.openQuery("SELECT * FROM LOGG_TBL");
// after
RowMetaAndData r = db.openQuery("SELECT * FROM LOG_TABLE"); // corrected table name

if (db == null || !db.isAutoCommit() && db.getConnection() == null) throw new IllegalStateException("connect first");
// validate table exists:
if (!db.checkTableExistsUnquoted(schema, table)) throw new IllegalStateException("table missing: " + table);

boolean isQueryReady(Database db) { try { return db.getConnection() != null && !db.getConnection().isClosed(); } catch (SQLException e) { return false; } }

try {
  RowMetaAndData r = db.openQuery(sql);
  // consume r
} catch (KettleDatabaseException e) {
  log.error("openQuery failed for SQL: " + sql, e);
  throw new RuntimeException("Query failed, SQL=" + sql, e);
}

When it happens

Trigger: Calling Database.openQuery(sql) with SQL that fails to execute (syntax error, missing table/column, bad connection) or that returns no rows, so the 'if (row != null)' branch is skipped and the else-branch throws.

Common situations: Typos in generated SQL, querying a table that does not exist on the target database, insufficient privileges, using a dialect-specific SQL that the connected DB rejects, or a closed/failed connection.

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

• An error occurred executing SQL:
• Couldn't execute SQL:
• Couldn't find any rows because of an error :
• Couldn't get a result because of an error :
• Couldn't prepare statement:

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/ee922cc7aa38f1e7. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/pentaho/di/core/database/Database.java:3633

      if ( pstmt != null ) {
        try {
          pstmt.close();
        } catch ( Exception e ) {
          throw new KettleDatabaseException( "Unable to close prepared statement pstmt", e );
        }
        pstmt = null;
      }
      if ( selStmt != null ) {
        try {
          selStmt.close();
        } catch ( Exception e ) {
          throw new KettleDatabaseException( "Unable to close prepared statement sel_stmt", e );
        }
        selStmt = null;
      }
      return new RowMetaAndData( rowMeta, row );
    } else {
      throw new KettleDatabaseException( "error opening resultset for query: " + sql );
    }
  }

  public RowMeta getMetaFromRow( Object[] row, ResultSetMetaData md ) throws SQLException, KettleDatabaseException {
    RowMeta meta = new RowMeta();

    for ( int i = 0; i < md.getColumnCount(); i++ ) {
      ValueMetaInterface valueMeta = getValueFromSQLType( md, i + 1, true, false );
      meta.addValueMeta( valueMeta );
    }

    return meta;
  }

  public RowMetaAndData getOneRow( String sql, RowMetaInterface param, Object[] data ) throws KettleDatabaseException {
    ResultSet rs = openQuery( sql, param, data );
    if ( rs != null ) {
      Object[] row = getRow( rs ); // One value: a number;

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