编写一个基于SQLite3的通讯录管理系统。本系统能实现添加记录、修改记录、删除记录、查询记录基本功能。

好的，我可以为您提供一个Python实现的基于SQLite3的通讯录管理系统。在开始之前，你需要先安装sqlite3和prettytable库。

代码如下：

import sqlite3
from prettytable import PrettyTable

# 连接数据库
conn = sqlite3.connect('address_book.db')
c = conn.cursor()

# 创建表
c.execute('''CREATE TABLE IF NOT EXISTS contacts
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
              name TEXT NOT NULL,
              phone TEXT NOT NULL,
              email TEXT)''')

# 添加记录
def add_contact(name, phone, email):
    c.execute("INSERT INTO contacts (name, phone, email) VALUES (?, ?, ?)", (name, phone, email))
    conn.commit()

# 修改记录
def update_contact(id, name, phone, email):
    c.execute("UPDATE contacts SET name=?, phone=?, email=? WHERE id=?", (name, phone, email, id))
    conn.commit()

# 删除记录
def delete_contact(id):
    c.execute("DELETE FROM contacts WHERE id=?", (id,))
    conn.commit()

# 查询记录
def search_contacts(keyword):
    c.execute("SELECT * FROM contacts WHERE name LIKE ? or phone LIKE ? or email LIKE ?", ('%'+keyword+'%', '%'+keyword+'%', '%'+keyword+'%'))
    rows = c.fetchall()
    if len(rows) == 0:
        print("No contacts found.")
    else:
        table = PrettyTable(['ID', 'Name', 'Phone', 'Email'])
        for row in rows:
            table.add_row(row)
        print(table)

# 显示所有记录
def show_all_contacts():
    c.execute("SELECT * FROM contacts")
    rows = c.fetchall()
    if len(rows) == 0:
        print("No contacts found.")
    else:
        table = PrettyTable(['ID', 'Name', 'Phone', 'Email'])
        for row in rows:
            table.add_row(row)
        print(table)

# 主程序
while True:
    print("1. Add contact")
    print("2. Update contact")
    print("3. Delete contact")
    print("4. Search contacts")
    print("5. Show all contacts")
    print("0. Exit")
    choice = input("Enter your choice: ")
    
    if choice == '1':
        name = input("Enter name: ")
        phone = input("Enter phone: ")
        email = input("Enter email (optional): ")
        add_contact(name, phone, email)
        print("Contact added successfully.")
        
    elif choice == '2':
        id = input("Enter ID of contact to update: ")
        name = input("Enter name (press enter to keep the current value): ")
        phone = input("Enter phone (press enter to keep the current value): ")
        email = input("Enter email (press enter to keep the current value): ")
        old_data = c.execute("SELECT * FROM contacts WHERE id=?", (id,)).fetchall()
        if len(old_data) == 0:
            print("Contact not found.")
        else:
            if name == '':
                name = old_data[0][1]
            if phone == '':
                phone = old_data[0][2]
            if email == '':
                email = old_data[0][3]
            update_contact(id, name, phone, email)
            print("Contact updated successfully.")
        
    elif choice == '3':
        id = input("Enter ID of contact to delete: ")
        delete_contact(id)
        print("Contact deleted successfully.")
        
    elif choice == '4':
        keyword = input("Enter keyword to search: ")
        search_contacts(keyword)
        
    elif choice == '5':
        show_all_contacts()
        
    elif choice == '0':
        break
        
    else:
        print("Invalid choice.")
        
# 关闭数据库连接
conn.close()

使用方法：

1. 运行程序后，会显示一个菜单，包括添加、修改、删除、查询、显示所有记录和退出等选项。
2. 选择相应的选项，按照提示输入信息。
3. 添加、修改和删除操作完成后，程序会自动更新数据库中的数据。
4. 查询和显示所有记录操作会返回相应的结果。

注意事项：

1. 数据库文件 `address_book.db` 和程序文件在同一目录下。
2. 在使用查询和显示所有记录功能时，如果没有符合条件的记录，则会提示“未找到联系人”。