Fix question mark conversion bug (#60)

filter.go

@@ -70,15 +70,30 @@ type SeqFilter struct {
 	Start  int
 }
 
+func convertQuestionMark(sql, prefix string, start int) string {
+	var buf strings.Builder
+	var beginSingleQuote bool
+	var beginTransfer bool
+	var index = start
+	for _, c := range sql {
+		if !beginSingleQuote && c == '?' {
+			buf.WriteString(fmt.Sprintf("%s%v", prefix, index))
+			index++
+		} else {
+			if c == '\\' {
+				beginTransfer = true
+			} else {
+				if !beginTransfer && c == '\'' {
+					beginSingleQuote = !beginSingleQuote
+				}
+				beginTransfer = false
+			}
+			buf.WriteRune(c)
+		}
+	}
+	return buf.String()
+}
+
 func (s *SeqFilter) Do(sql string, dialect Dialect, table *Table) string {
-	segs := strings.Split(sql, "?")
-	size := len(segs)
-	res := ""
-	for i, c := range segs {
-		if i < size-1 {
-			res += c + fmt.Sprintf("%s%v", s.Prefix, i+s.Start)
-		}
-	}
-	res += segs[size-1]
-	return res
+	return convertQuestionMark(sql, s.Prefix, s.Start)
 }

filter_test.go

@@ -23,3 +23,14 @@ func TestQuoteFilter_Do(t *testing.T) {
 		res,
 	)
 }
+
+func TestSeqFilter(t *testing.T) {
+	var kases = map[string]string{
+		"SELECT * FROM TABLE1 WHERE a=? AND b=?":                               "SELECT * FROM TABLE1 WHERE a=$1 AND b=$2",
+		"SELECT 1, '???', '2006-01-02 15:04:05' FROM TABLE1 WHERE a=? AND b=?": "SELECT 1, '???', '2006-01-02 15:04:05' FROM TABLE1 WHERE a=$1 AND b=$2",
+		"select '1\\'?' from issue":                                            "select '1\\'?' from issue",
+	}
+	for sql, result := range kases {
+		assert.EqualValues(t, result, convertQuestionMark(sql, "$", 1))
+	}
+}