Order ID specifications
- **Format requirements**: pure numeric format
- **Length limit**: usually 6-12 digits
- **Uniqueness**: unique in the global scope
- **Generation rules**: automatically generated by the system
User ID specifications
- **Format requirements**: pure numeric format
- **Length limit**: usually 6-10 digits
- **Uniqueness**: unique in the global scope
- **Association**: associated with the user system
Amount specifications
- **Accuracy requirements**: keep 2 decimal places
- **Currency unit**: RMB (yuan)
- **Display format**: ¥123.45
- **Calculation accuracy**: avoid floating point accuracy issues
Time specifications
- **Format requirements**: YYYY-MM-DD HH:mm:ss
- **Time zone processing**: use the system time zone uniformly
- **Display format**: display according to user preferences
- **Sorting rules**: sort in reverse chronological order