28.1.3 Implementing One-to-Many Relationships (cont.)

Novice programmers often replicate columns:
- Wastes space (1 or 2 items)
- Doesn't solve problem (4 or 12 items)

Poor design for Invoice Table
Invoice_ Number	Customer_ Number	Product_ Code1	Quantity1	Product_ Code2	Quantity2	Product_ Code3	Quantity3	Payment
`INTEGER`	`INTEGER`	`CHAR(10)`	`INTEGER`	`CHAR(10)`	`INTEGER`	`CHAR(10)`	`INTEGER`	`DECIMAL(10,2)`
11731	3175	116-064	3	257-535	1	643-119	2	0