用于显示结果的SQL查询

Question

以下是数据库中的表格：

Product     Type1       Type2       Type3       Manufacturer
Notebook    50 Pages    100 Pages   150 Pages   KP Mills
Pen         Blue        Black       Red         Parker

SQL Query应该以下列格式显示结果：

Product     Type        Manufacturer
Notebook    50 Pages    KP Mills
Notebook    100 Pages   KP Mills
Notebook    150 Pages   KP Mills
Pen         Blue        Parker
Pen         Black       Parker
Pen         Red         Parker

Answer 1

select product, 
       type1 as type,
       manufacturer
from the_table
union all
select product, 
       type2,
       manufacturer
from the_table
union all
select product, 
       type3,
       manufacturer
from the_table
order by product, type;