/
filter.go
43 lines (37 loc) · 897 Bytes
/
filter.go
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// Copyright 2019 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package dialects
import (
"fmt"
"strings"
)
// Filter is an interface to filter SQL
type Filter interface {
Do(sql string) string
}
// SeqFilter filter SQL replace ?, ? ... to $1, $2 ...
type SeqFilter struct {
Prefix string
Start int
}
func convertQuestionMark(sql, prefix string, start int) string {
var buf strings.Builder
var beginSingleQuote bool
var index = start
for _, c := range sql {
if !beginSingleQuote && c == '?' {
buf.WriteString(fmt.Sprintf("%s%v", prefix, index))
index++
} else {
if c == '\'' {
beginSingleQuote = !beginSingleQuote
}
buf.WriteRune(c)
}
}
return buf.String()
}
func (s *SeqFilter) Do(sql string) string {
return convertQuestionMark(sql, s.Prefix, s.Start)
}