result_columns.go

// Copyright 2017 The Cockroach Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the License.
//
// Author: Tamir Duberstein (tamird@gmail.com)
// Author: Andrei Matei (andreimatei1@gmail.com)

package sqlbase

import (
	"fmt"

	"github.com/cockroachdb/cockroach/pkg/sql/parser"
)

// ResultColumn contains the name and type of a SQL "cell".
type ResultColumn struct {
	Name string
	Typ  parser.Type

	// If set, this is an implicit column; used internally.
	Hidden bool

	// If set, a value won't be produced for this column; used internally.
	Omitted bool
}

// ResultColumns is the type used throughout the sql module to
// describe the column types of a table.
type ResultColumns []ResultColumn

// ResultColumnsFromColDescs converts ColumnDescriptors to ResultColumns.
func ResultColumnsFromColDescs(colDescs []ColumnDescriptor) ResultColumns {
	cols := make(ResultColumns, 0, len(colDescs))
	for _, colDesc := range colDescs {
		// Convert the ColumnDescriptor to ResultColumn.
		typ := colDesc.Type.ToDatumType()
		if typ == nil {
			panic(fmt.Sprintf("unsupported column type: %s", colDesc.Type.Kind))
		}

		hidden := colDesc.Hidden
		cols = append(cols, ResultColumn{Name: colDesc.Name, Typ: typ, Hidden: hidden})
	}
	return cols
}