code: func (e *ShowNextRowIDExec) Next(ctx context.Context, req *chunk.RecordBatch) error {
  	req.Reset()
  	if e.done {
  		return nil
  	}
  	is := domain.GetDomain(e.ctx).InfoSchema()
  	tbl, err := is.TableByName(e.tblName.Schema, e.tblName.Name)
  	if err != nil {
  		return err
  	}
  	colName := model.ExtraHandleName
  	for _, col := range tbl.Meta().Columns {
  		if mysql.HasAutoIncrementFlag(col.Flag) {
  			colName = col.Name
  			break
  		}
  	}
  	nextGlobalID, err := tbl.Allocator(e.ctx).NextGlobalAutoID(tbl.Meta().ID)
  	if err != nil {
  		return err
  	}
  	req.AppendString(0, e.tblName.Schema.O)
  	req.AppendString(1, e.tblName.Name.O)
  	req.AppendString(2, colName.O)
  	req.AppendInt64(3, nextGlobalID)
  	e.done = true
  	return nil
  }
docs: // Next implements the Executor Next interface.