github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/planner/orderby.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     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 planner
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"github.com/vescale/zgraph/expression"
    21  	"github.com/vescale/zgraph/parser/model"
    22  )
    23  
    24  // ByItem wraps a "by" item.
    25  type ByItem struct {
    26  	Expr      expression.Expression
    27  	AsName    model.CIStr
    28  	Desc      bool
    29  	NullOrder bool
    30  }
    31  
    32  // String implements fmt.Stringer interface.
    33  func (by *ByItem) String() string {
    34  	if by.Desc {
    35  		return fmt.Sprintf("%s true", by.Expr)
    36  	}
    37  	return by.Expr.String()
    38  }
    39  
    40  type LogicalSort struct {
    41  	baseLogicalPlan
    42  
    43  	ByItems []*ByItem
    44  }
    45  
    46  type PhysicalSort struct {
    47  	basePhysicalPlan
    48  
    49  	ByItems []*ByItem
    50  }