-
Notifications
You must be signed in to change notification settings - Fork 92
/
union.go
95 lines (80 loc) · 2.25 KB
/
union.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package ast
import (
"strings"
)
import (
"github.com/pkg/errors"
)
const (
_ UnionType = iota
UnionTypeAll
UnionTypeDistinct
)
var (
_ Statement = (*UnionSelectStatement)(nil)
_ Restorer = (*UnionSelectStatement)(nil)
)
var _unionTypeNames = [...]string{
UnionTypeAll: "ALL",
UnionTypeDistinct: "DISTINCT",
}
type UnionType uint8
func (u UnionType) String() string {
return _unionTypeNames[u]
}
type UnionSelectStatement struct {
First *SelectStatement
UnionStatementItems []*UnionStatementItem
OrderBy OrderByNode
}
func (u *UnionSelectStatement) Accept(visitor Visitor) (interface{}, error) {
return visitor.VisitUnionStatement(u)
}
func (u *UnionSelectStatement) Restore(flag RestoreFlag, sb *strings.Builder, args *[]int) error {
if err := u.First.Restore(flag, sb, args); err != nil {
return errors.WithStack(err)
}
for _, it := range u.UnionStatementItems {
switch it.Type {
case UnionTypeDistinct:
sb.WriteString(" UNION ")
case UnionTypeAll:
sb.WriteString(" UNION ALL ")
default:
panic("unreachable")
}
if err := it.Stmt.Restore(flag, sb, args); err != nil {
return errors.WithStack(err)
}
}
if u.OrderBy != nil {
sb.WriteString(" ORDER BY ")
if err := u.OrderBy.Restore(flag, sb, args); err != nil {
return errors.WithStack(err)
}
}
return nil
}
func (u *UnionSelectStatement) Mode() SQLType {
return SQLTypeUnion
}
type UnionStatementItem struct {
Type UnionType
Stmt *SelectStatement
}