Refactor dummy driver QuoteTo method

utils/tests/dummy_dialecter.go

@@ -31,9 +31,51 @@ func (DummyDialector) BindVarTo(writer clause.Writer, stmt *gorm.Statement, v in
 }
 
 func (DummyDialector) QuoteTo(writer clause.Writer, str string) {
-	writer.WriteByte('`')
+	var (
-	writer.WriteString(str)
+		underQuoted, selfQuoted bool
-	writer.WriteByte('`')
+		continuousBacktick      int8
+		shiftDelimiter          int8
+	)
+
+	for _, v := range []byte(str) {
+		switch v {
+		case '`':
+			continuousBacktick++
+			if continuousBacktick == 2 {
+				writer.WriteString("``")
+				continuousBacktick = 0
+			}
+		case '.':
+			if continuousBacktick > 0 || !selfQuoted {
+				shiftDelimiter = 0
+				underQuoted = false
+				continuousBacktick = 0
+				writer.WriteString("`")
+			}
+			writer.WriteByte(v)
+			continue
+		default:
+			if shiftDelimiter-continuousBacktick <= 0 && !underQuoted {
+				writer.WriteByte('`')
+				underQuoted = true
+				if selfQuoted = continuousBacktick > 0; selfQuoted {
+					continuousBacktick -= 1
+				}
+			}
+
+			for ; continuousBacktick > 0; continuousBacktick -= 1 {
+				writer.WriteString("``")
+			}
+
+			writer.WriteByte(v)
+		}
+		shiftDelimiter++
+	}
+
+	if continuousBacktick > 0 && !selfQuoted {
+		writer.WriteString("``")
+	}
+	writer.WriteString("`")
 }
 
 func (DummyDialector) Explain(sql string, vars ...interface{}) string {