如何在sql中获得最少和最昂贵的书籍的价值？

Question

如何为每个基于零售价格的出版商获取最少和最昂贵的图书的价值？

我已经查询了下面的表格。然而，我只是不知道如何得到，我认为这将是最后5行，这是一个结果。另外，如果我理解正确的问题。

select name, title, retail, sum(quantity) 
from books full outer join orderitems using(isbn) 
join publisher using(pubid) 
group by name, title, retail 
order by retail; 

NAME     TITLE        RETAIL SUM(QUANTITY) 
----------------------- ------------------------------ ---------- ------------- 
REED-N-RITE    BIG BEAR AND LITTLE DOVE    8.95    4 
READING MATERIALS INC. COOKING WITH MUSHROOMS    19.95    8 
PRINTING IS US   REVENGE OF MICKEY      22    5 
AMERICAN PUBLISHING  HANDCRANKED COMPUTERS     25    2 
READING MATERIALS INC. THE WOK WAY TO COOK     28.75 
READING MATERIALS INC. HOW TO GET FASTER PIZZA    29.95 
READING MATERIALS INC. BODYBUILD IN 10 MINUTES A DAY  30.95    1 
PRINTING IS US   HOW TO MANAGE THE MANAGER   31.95    1 
REED-N-RITE    SHORTEST POEMS      39.95    1 
PUBLISH OUR WAY   E-BUSINESS THE EASY WAY    54.5    2 
AMERICAN PUBLISHING  DATABASE IMPLEMENTATION    55.95    7 
PUBLISH OUR WAY   BUILDING A CAR WITH TOOTHPICKS  59.95 
AMERICAN PUBLISHING  HOLY GRAIL OF ORACLE    75.95    3 
REED-N-RITE    PAINLESS CHILD-REARING    89.95    6 

Answer 1

因为你还没有表现出我们的其他表硬一点讲，但如何：

select publisher, min(retail), max(retail) 
from books join orderitems using(isbn) 
join publisher using(pubid) 
group by publisher; 

要点：

• 你想要一个最小和一个最大每个出版商 so发布商集团
• min(retail)给你的最小值对于该组中的所有图书（发布者）为0，以便告诉您每个发布者发布的最便宜的图书。
• 同样，max告诉你最便宜的