github.com/rohankumardubey/aresdb@v0.0.2-0.20190517170215-e54e3ca06b9c/query/sql/tree/AliasedRelation.go (about)

     1  //  Copyright (c) 2017-2018 Uber Technologies, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tree
    16  
    17  import (
    18  	"github.com/uber/aresdb/query/sql/util"
    19  )
    20  
    21  // AliasedRelation is alias relation
    22  type AliasedRelation struct {
    23  	IRelation
    24  	Relation    IRelation
    25  	Alias       *Identifier
    26  	ColumnNames []*Identifier
    27  }
    28  
    29  // NewAliasedRelation creates NewAliasedRelation
    30  func NewAliasedRelation(
    31  	location *NodeLocation,
    32  	relation IRelation,
    33  	alias *Identifier,
    34  	columns []*Identifier) *AliasedRelation {
    35  	util.RequireNonNull(relation, "relation is null")
    36  	util.RequireNonNull(alias, "alias is null")
    37  	return &AliasedRelation{
    38  		NewRelation(location),
    39  		relation,
    40  		alias,
    41  		columns,
    42  	}
    43  }
    44  
    45  // Accept accepts visitor
    46  func (n *AliasedRelation) Accept(visitor AstVisitor, ctx interface{}) interface{} {
    47  	return visitor.VisitAliasedRelation(n, ctx)
    48  }