forked from ulule/loukoum
/
between.go
66 lines (57 loc) · 1.63 KB
/
between.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
package stmt
import (
"github.com/ulule/loukoum/types"
)
// Between is a BETWEEN expression.
type Between struct {
Identifier Identifier
Operator ComparisonOperator
From Expression
And LogicalOperator
To Expression
}
// NewBetween returns a new Between instance using an inclusive operator.
func NewBetween(identifier Identifier, from, to Expression) Between {
return Between{
Identifier: identifier,
Operator: NewComparisonOperator(types.Between),
From: from,
And: NewAndOperator(),
To: to,
}
}
// NewNotBetween returns a new Between instance using an exclusive operator.
func NewNotBetween(identifier Identifier, from, to Expression) Between {
return Between{
Identifier: identifier,
Operator: NewComparisonOperator(types.NotBetween),
From: from,
And: NewAndOperator(),
To: to,
}
}
func (Between) expression() {}
// Write exposes statement as a SQL query.
func (between Between) Write(ctx types.Context) {
if between.IsEmpty() {
panic("loukoum: expression is undefined")
}
ctx.Write("(")
between.Identifier.Write(ctx)
ctx.Write(" ")
between.Operator.Write(ctx)
ctx.Write(" ")
between.From.Write(ctx)
ctx.Write(" ")
between.And.Write(ctx)
ctx.Write(" ")
between.To.Write(ctx)
ctx.Write(")")
}
// IsEmpty returns true if statement is undefined.
func (between Between) IsEmpty() bool {
return between.Identifier.IsEmpty() || between.Operator.IsEmpty() || between.And.IsEmpty() ||
between.From == nil || between.To == nil || between.From.IsEmpty() || between.To.IsEmpty()
}
// Ensure that Between is an Expression
var _ Expression = Between{}