genmai.go
func (db *DB) hasSkipTag(field *reflect.StructField) bool {
	if field.Tag.Get(dbTag) == skipTag {
		return true
	}
	return false
}
func (db *DB) hasSkipTag(field *reflect.StructField) bool {
	if field.Tag.Get(dbTag) == skipTag {
		return true
	}
	return false
}
// hasSkipTag returns whether the struct field has the "-" tag.