此脚本自动创建 MySQL 数据库的备份、恢复它们以及管理目标 MySQL 服务器上的数据库和用户创建。

import subprocess
import datetime
import sys
import os

def check_and_create_database(host, port, username, password, database):
    # Command to check if the database exists
    check_database_command = f"mysql -sN --host={host} --port={port} --user={username} --password={password} -e \"SELECT EXISTS(SELECT 1 FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = '{database}')\" 2>/dev/null"

    # Execute the command
    output = subprocess.check_output(check_database_command, shell=True)

    # If the output contains b'1', the database exists
    if b'1' in output:
        subprocess.run(check_database_command, shell=True, check=True)
        print(f"Database '{database}' already exists.")
        sys.exit(1)
    else:
        # If the command fails, the database does not exist
        print(f"Database '{database}' does not exist. Creating...")

        # Command to create the database
        create_database_command = f"mysql --host={host} --port={port} --user={username} --password={password} -e 'CREATE DATABASE {database}' 2>/dev/null"
        subprocess.run(create_database_command, shell=True)

def check_and_create_user(host, port, username, password, database, new_username, new_password):
    # Command to check if the user exists
    check_user_command = f"mysql -sN --host={host} --port={port} --user={username} --password={password} -e \"SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '{new_username}')\" 2>/dev/null"

    # Execute the command
    output = subprocess.check_output(check_user_command, shell=True)

    # If the output contains b'1', the user exists
    if b'1' in output:
        print(f"User '{new_username}' already exists.")
        sys.exit(1)
    else:
        # The user does not exist, create it
        print(f"User '{new_username}' does not exist. Creating...")

        # Command to create the user and grant privileges
        create_user_command = f"mysql --host={host} --port={port} --user={username} --password={password} -e \"CREATE USER '{new_username}'@'%' IDENTIFIED BY '{new_password}'; GRANT ALL PRIVILEGES ON {database}.* TO '{new_username}'@'%'; FLUSH PRIVILEGES;\" 2>/dev/null"
        subprocess.run(create_user_command, shell=True)

def backup_mysql_database(host, port, username, password, database, backup_path):

    # Check if the backup directory exists
    if not os.path.exists(backup_path):
        print(f"Error: Backup directory '{backup_path}' does not exist.")
        sys.exit(1)

    # Create a filename for the backup with the current date and time
    timestamp = datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
    backup_file = f"{backup_path}/{database}_{timestamp}.sql"

    # Command to create a database backup using mysqldump
    dump_command = f"mysqldump --no-tablespaces --host={host} --port={port} --user={username} --password={password} {database} > {backup_file} 2>/dev/null"

    # Execute the mysqldump command
    subprocess.run(dump_command, shell=True)

    return backup_file

def restore_mysql_database(host, port, username, password, database, backup_file):
    # Command to restore a database from a backup using mysql
    restore_command = f"mysql --host={host} --port={port} --user={username} --password={password} {database} /dev/null"

    # Execute the mysql command
    subprocess.run(restore_command, shell=True)

def main():
    # Connection parameters to the source MySQL database
    source_host = "127.0.0.1"
    source_port = "3309"
    source_username = "my_user"
    source_password = "my_password"
    source_database = "my_database"

    # Connection parameters to the target MySQL database
    target_host = "127.0.0.1"
    target_port = "3309"
    new_username = "new_username"
    new_password = "new_password"
    target_database = "my_database_two"

    target_username = "root"
    target_password = "root_password"

    # Path to save the backup locally
    backup_path = "my_dbs_dumps"

    # Check if source_database is different from target_database
    if source_database == target_database:
        print("Error: Source database should be different from target database.")
        sys.exit(1)

    # Check and create the target database if it does not exist
    check_and_create_database(target_host, target_port, target_username, target_password, target_database)

    # Check and create the target user if it does not exist
    check_and_create_user(target_host, target_port, target_username, target_password, target_database, new_username, new_password)

    # Create a backup of the MySQL database
    backup_file = backup_mysql_database(source_host, source_port, source_username, source_password, source_database, backup_path)
    print(f"Database backup created: {backup_file}")

    # Restore the database on the target server from the backup
    restore_mysql_database(target_host, target_port, target_username, target_password, target_database, backup_file)
    print("Database backup restored on the target server.")

if __name__ == "__main__":
    main()

check_and_create_database:
此函数检查 MySQL 服务器上是否存在数据库。如果数据库不存在，则会创建它。它需要主机、端口、用户名、密码和数据库名称等参数来检查或创建。

check_and_create_user:
与数据库函数一样，该函数检查 MySQL 服务器上是否存在用户。如果用户不存在，它将创建用户并授予特定数据库的权限。它还接受主机、端口、用户名、密码、数据库名称、新用户名和新密码等参数。

backup_mysql_database:
此函数使用 mysqldump 执行 MySQL 数据库的备份。它接受主机、端口、用户名、密码、数据库名称和保存备份文件的路径等参数。

restore_mysql_database:
此函数从备份文件恢复 MySQL 数据库。它接受主机、端口、用户名、密码、数据库名称和备份文件路径等参数。

主要的：
这是脚本的主要功能。它为源和目标 MySQL 数据库设置参数，包括连接详细信息、数据库名称和备份路径。然后，它执行检查以确保源数据库和目标数据库不同，如果目标数据库和用户不存在，则创建目标数据库和用户，创建源数据库的备份，最后将备份恢复到目标数据库。

此外，该脚本使用 subprocess 模块执行 MySQL 操作（mysql、mysqldump）的 shell 命令，并执行错误处理和输出重定向（2>/dev/null）以抑制不必要的输出。

如果您正在使用 MySQL 数据库并想要创建自动化，此代码将为您提供帮助。

此代码代表了一个很好的起始模板，用于创建管理 MySQL 数据库的自动化脚本。

dmi@dmi-laptop:~/my_python$ python3 mysql_backup_restore.py 
Database 'my_database_two' does not exist. Creating...
User 'new_username' does not exist. Creating...
Database backup created: my_dbs_dumps/my_database_2024-05-13_20-05-24.sql
Database backup restored on the target server.
dmi@dmi-laptop:~/my_python$ 

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