code: func (s *session) FieldList(tableName string) ([]*ast.ResultField, error) {
  	is := executor.GetInfoSchema(s)
  	dbName := model.NewCIStr(s.GetSessionVars().CurrentDB)
  	tName := model.NewCIStr(tableName)
  	table, err := is.TableByName(dbName, tName)
  	if err != nil {
  		return nil, err
  	}
  
  	cols := table.Cols()
  	fields := make([]*ast.ResultField, 0, len(cols))
  	for _, col := range table.Cols() {
  		rf := &ast.ResultField{
  			ColumnAsName: col.Name,
  			TableAsName:  tName,
  			DBName:       dbName,
  			Table:        table.Meta(),
  			Column:       col.ColumnInfo,
  		}
  		fields = append(fields, rf)
  	}
  	return fields, nil
  }
docs: // FieldList returns fields list of a table.