github.com/rohankumardubey/aresdb@v0.0.2-0.20190517170215-e54e3ca06b9c/query/sql/tree/JoinUsing.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  // JoinUsing is natural join
    22  type JoinUsing struct {
    23  	// IJoinCriteria is interface
    24  	IJoinCriteria
    25  	Columns []*Identifier
    26  }
    27  
    28  // NewJoinUsing creates JoinUsing
    29  func NewJoinUsing(columns []*Identifier) *JoinUsing {
    30  	util.RequireNonNull(columns, "columns is null")
    31  	return &JoinUsing{
    32  		Columns: columns,
    33  	}
    34  }
    35  
    36  // GetNodes returns empty
    37  func (j *JoinUsing) GetNodes() []INode {
    38  	return []INode{}
    39  }