/
select.go
59 lines (51 loc) · 1.07 KB
/
select.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
package clause
// Select select attrs when querying, updating, creating
type Select struct {
Distinct bool
Columns []Column
Expression Expression
}
func (s Select) Name() string {
return "SELECT"
}
func (s Select) Build(builder Builder) {
if len(s.Columns) > 0 {
if s.Distinct {
builder.WriteString("DISTINCT ")
}
for idx, column := range s.Columns {
if idx > 0 {
builder.WriteByte(',')
}
builder.WriteQuoted(column)
}
} else {
builder.WriteByte('*')
}
}
func (s Select) MergeClause(clause *Clause) {
if s.Expression != nil {
if s.Distinct {
if expr, ok := s.Expression.(Expr); ok {
expr.SQL = "DISTINCT " + expr.SQL
clause.Expression = expr
return
}
}
clause.Expression = s.Expression
} else {
clause.Expression = s
}
}
// CommaExpression represents a group of expressions separated by commas.
type CommaExpression struct {
Exprs []Expression
}
func (comma CommaExpression) Build(builder Builder) {
for idx, expr := range comma.Exprs {
if idx > 0 {
_, _ = builder.WriteString(", ")
}
expr.Build(builder)
}
}