func (d testDialector) QuoteTo(writer clause.Writer, s string)         { writer.WriteString(s) }
func (d testDialector) Explain(sql string, vars ...interface{}) string { return sql }

// newTestDB returns a minimal *DB with an initialized Statement suitable for unit tests
func newTestDB() *gorm.DB {
	d := testDialector{}
	cfg := &gorm.Config{Dialector: d}
	db := &gorm.DB{Config: cfg}
	stmt := &gorm.Statement{
		DB:       db,