编写程序实现对图书信息表的增删改查操作。 需求分析：现有图书信息表bookinfo（序号，图书编号，图书名称，作者，出版社，单价，出版日期，ISBN，库存数量）。写程序实现对该表的增删改查操作。

在编写程序实现对图书信息表的增删改查操作时，通常会使用结构化查询语言（SQL），因为它是数据库管理的标准语言。这里是一个简单的示例，我们将使用Python结合SQLite数据库来演示如何实现这个功能。假设我们已经有一个名为`BookInfo`的类表示图书信息，并创建了一个SQLite连接。

**1. 插入（增）操作：**

class BookInfo:
    def __init__(self, book_id, isbn, title, author, publisher, price, publication_date, stock):
        self.book_id = book_id
        self.isbn = isbn
        self.title = title
        self.author = author
        self.publisher = publisher
        self.price = price
        self.publication_date = publication_date
        self.stock = stock

def add_book(book_info):
    conn = sqlite3.connect('library.db')
    cursor = conn.cursor()
    query = "INSERT INTO bookinfo VALUES (?, ?, ?, ?, ?, ?, ?, ?)"
    cursor.execute(query, (book_info.book_id, book_info.isbn, book_info.title, book_info.author, book_info.publisher, book_info.price, book_info.publication_date, book_info.stock))
    conn.commit()
    conn.close()

# 使用示例
add_book(BookInfo(1, '001', 'Python入门', '张三', '人民邮电出版社', 59.9, '2022-01-01', 100))

**2. 删除（减）操作：**

def delete_book(isbn):
    conn = sqlite3.connect('library.db')
    cursor = conn.cursor()
    query = "DELETE FROM bookinfo WHERE isbn = ?"
    cursor.execute(query, (isbn,))
    conn.commit()
    conn.close()

**3. 更新（改）操作：**

def update_book(book_id, field_name, new_value):
    conn = sqlite3.connect('library.db')
    cursor = conn.cursor()
    query = f"UPDATE bookinfo SET {field_name} = ? WHERE book_id = ?"
    cursor.execute(query, (new_value, book_id))
    conn.commit()
    conn.close()

**4. 查询（查）操作：**

def get_books_by_author(author):
    conn = sqlite3.connect('library.db')
    cursor = conn.cursor()
    query = "SELECT * FROM bookinfo WHERE author = ?"
    cursor.execute(query, (author,))
    books = cursor.fetchall()
    conn.close()
    return books

# 示例
books_by_author = get_books_by_author('张三')