加入Count和select查询

Question

表格类型

 GENRE_CATEGORY     DESCRIPTION
 --------------     ----------------------
 C100           Information Technology
 C200           Novel
 C300           Cookery
 C400           Lifestyle

表格书

 ISBN           TITLE               PAGE_NUMBER     PUBLICATION_YEAR    PUBLISHER_CODE  GENRE_CATEGORY
 ------------   -----------------   -----------     ----------------    --------------  --------------
 123-0-12-374   Rainbow Mountain            200              2011      P2001                 C200
 989-2-96-545   Data Mining                 340              2012      P2002            C100
 718-8-16-555   Asian Food                  280              2013      P3002            C300
 674-9-90-345   Yoga for the mind           180             2016       P2002            C400
 900-0-88-767   Finding Rainbow             250             2016       P2001            C200
 888-9-55-447   Pastry Heaven               200             2016       P3002            C300

我需要编写什么sql语句来生成一个包含发布商代码，描述，书籍数量的表格（计算使用计数的书籍数量）。 该表必须显示有多少本书适用于小说，信息技术，生活方式和烹饪。我花了两个小时试图弄清楚该怎么做请帮帮我

select Publisher_Code,Description, count(genre_category)
from genre
INNER Join book
ON genre.genre_category=book.genre_category
where(genre.genre_category=book.genre_category);

The output must look like this

Answer 1

我认为这就是你要找的......

select Publisher_Code, Description, count(*)
from genre
INNER Join book
   ON genre.genre_category=book.genre_category
GROUP BY Publisher_Code, Description;