code: func FindIndexByColName(t table.Table, name string) table.Index {
  	for _, idx := range t.Indices() {
  		// only public index can be read.
  		if idx.Meta().State != model.StatePublic {
  			continue
  		}
  
  		if len(idx.Meta().Columns) == 1 && strings.EqualFold(idx.Meta().Columns[0].Name.L, name) {
  			return idx
  		}
  	}
  	return nil
  }
docs: // FindIndexByColName implements table.Table FindIndexByColName interface.