以下任务的 SQL 语句是什么：

Question

列出出版平装书的出版商以及每个出版商出版的平装书数量。我在计算每个出版商的平装本时遇到了困难。任何帮助都感激不尽。谢谢！

亨利图书 Table 架构

**author**          
    authorNum       INT             PRIMARY KEY 
    authorLast      VARCHAR(12),    
    authorFirst     VARCHAR(10)

**publisher**           
    publisherCode       CHAR(3)         PRIMARY KEY 
    publisherName       VARCHAR(25)     
    city                VARCHAR(20)

**book**            
    bookCode            CHAR(4)         PRIMARY KEY 
    title               VARCHAR(40)     
    publisherCode       CHAR(3)     
    bookType            CHAR(3)     
    paperback           ENUM('No', 'Yes') 

    CONSTRAINT book_fk_publisher 
        FOREIGN KEY (publisherCode) 
        REFERENCES publisher(publisherCode) 

**branch**      
    branchNum       INT          
    branchName      VARCHAR(50)  
    branchLocation  VARCHAR(50) 

**copy** 
    bookCode        CHAR(4)  
    branchNum       INT  
    copyNum         INT     PRIMARY KEY 
    quality         ENUM('Excellent', 'Fair', 'Good', 'Poor') 
    price           DECIMAL(8,2) 

    CONSTRAINT copy_pk 
        PRIMARY KEY (bookCode, branchNum, copyNum 
    CONSTRAINT copy_fk_book 
        FOREIGN KEY (bookCode) 
        REFERENCES book(bookCode),      
    CONSTRAINT copy_fk_branch 
        FOREIGN KEY (branchNum) 
        REFERENCES branch(branchNum) 

**wrote** 
    bookCode   CHAR(4)  
    authorNum  INT  
    sequence   INT 

    PRIMARY KEY (BookCode, AuthorNum), 
    CONSTRAINT wrote_fk_book 
        FOREIGN KEY (bookCode) 
        REFERENCES book(bookCode), 
    CONSTRAINT wrote_fk_author 
        FOREIGN KEY (authorNum) 
        REFERENCES author(authorNum)

这是我的：

SELECT publisherName, COUNT(paperback) AS "numPaperback"
FROM publisher, book
WHERE paperback = "Yes";

Answer 1

看来你是新来的。所以我会试着引导你完成这个...

将出版商table加入图书table。他们共享一个出版商代码，link 他们在一起。
使用 where 子句按书籍类型过滤加入的 table。你想要平装书。
对出版商代码和名称执行group by，然后count图书栏目

这对您有帮助吗？

Answer 2

您必须使用 count(*) 和 Group by 来计算平装书的数量。这就是我编写查询的方式：

SELECT publisherName,count(*) AS "Number of paperbacks" FROM
publisher p INNER JOIN book b WHERE
p.publisherCode=b.publisherCode AND b.paperback="Yes"
GROUP BY publisherName;

以下任务的 SQL 语句是什么：

What is the SQL statement for the following task:

mysql

sql

workbench