hunt.sql.ast.statement.SQLSelectOrderByItem source code

1 /*
2  * Copyright 2015-2018 HuntLabs.cn
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 module hunt.sql.ast.statement.SQLSelectOrderByItem;
17 
18 import hunt.sql.ast.SQLExpr;
19 import hunt.sql.ast.SQLObjectImpl;
20 import hunt.sql.ast.SQLOrderingSpecification;
21 import hunt.sql.ast.SQLReplaceable;
22 import hunt.sql.visitor.SQLASTVisitor;
23 import hunt.sql.ast.statement.SQLSelectItem;
24 
25 public  class SQLSelectOrderByItem : SQLObjectImpl , SQLReplaceable {
26 
27     protected SQLExpr                  expr;
28     protected string                   collate;
29     protected SQLOrderingSpecification type;
30     protected NullsOrderType           nullsOrderType;
31 
32     protected SQLSelectItem  resolvedSelectItem;
33 
34     public this(){
35 
36     }
37 
38     public this(SQLExpr expr){
39         this.setExpr(expr);
40     }
41 
42     public SQLExpr getExpr() {
43         return this.expr;
44     }
45 
46     public void setExpr(SQLExpr expr) {
47         if (expr !is null) {
48             expr.setParent(this);
49         }
50         this.expr = expr;
51     }
52 
53     public string getCollate() {
54         return collate;
55     }
56 
57     public void setCollate(string collate) {
58         this.collate = collate;
59     }
60 
61     public SQLOrderingSpecification getType() {
62         return this.type;
63     }
64 
65     public void setType(SQLOrderingSpecification type) {
66         this.type = type;
67     }
68     
69     public NullsOrderType getNullsOrderType() {
70         return this.nullsOrderType;
71     }
72 
73     public void setNullsOrderType(NullsOrderType nullsOrderType) {
74         this.nullsOrderType = nullsOrderType;
75     }
76 
77     override  protected void accept0(SQLASTVisitor visitor) {
78         if (visitor.visit(this)) {
79             acceptChild(visitor, this.expr);
80         }
81 
82         visitor.endVisit(this);
83     }
84 
85     override
86     public size_t toHash() @trusted nothrow {
87          int prime = 31;
88         size_t result = 1;
89         result = prime * result + hashOf(collate);
90         result = prime * result + ((expr is null) ? 0 : (cast(Object)expr).toHash());
91         result = prime * result + (type is null) ? 0 : type.toHash();
92         return result;
93     }
94 
95     override
96     public bool opEquals(Object obj) {
97         if (this == obj) return true;
98         if (obj is null) return false;
99         if (typeid(this) != typeid(obj)) return false;
100         SQLSelectOrderByItem other = cast(SQLSelectOrderByItem) obj;
101         if (collate is null) {
102             if (other.collate !is null) return false;
103         } else if (!(collate == other.collate)) return false;
104         if (expr is null) {
105             if (other.expr !is null) return false;
106         } else if (!(cast(Object)(expr)).opEquals(cast(Object)(other.expr))) return false;
107         if (type != other.type) return false;
108         return true;
109     }
110 
111     override
112     public bool replace(SQLExpr expr, SQLExpr target) {
113         if (this.expr == expr) {
114             this.setExpr(target);
115             return true;
116         }
117         return false;
118     }
119 
120     public static struct NullsOrderType {
121         enum NullsOrderType NullsFirst = NullsOrderType("NULLS FIRST");
122         enum NullsOrderType NullsLast = NullsOrderType("NULLS LAST");
123 
124         private string _name;
125         this(string name)
126         {
127             _name = name;
128         }
129 
130         @property string name()
131         {
132             return _name;
133         }
134 
135         public string toFormalString() {
136             return _name;
137         }
138     }
139 
140     override public SQLSelectOrderByItem clone() {
141         SQLSelectOrderByItem x = new SQLSelectOrderByItem();
142         if (expr !is null) {
143             x.setExpr(expr.clone());
144         }
145         x.collate = collate;
146         x.type = type;
147         x.nullsOrderType = nullsOrderType;
148         return x;
149     }
150 
151     public SQLSelectItem getResolvedSelectItem() {
152         return resolvedSelectItem;
153     }
154 
155     public void setResolvedSelectItem(SQLSelectItem resolvedSelectItem) {
156         this.resolvedSelectItem = resolvedSelectItem;
157     }
158 }