mysql 数据的导出以及导入。以及数据库的清空

import os
import subprocess
import pymysql.cursors


# 注释的为此次导出为空的表，根据实际情况自行判断
# 根据 show tables 将所有的表名存入这个列表;
ALL_TABLES = []

def subprocess_popen(statement):
    file_out = subprocess.Popen(statement, shell=True, stdout=subprocess.PIPE)
    break_count = 0
    while True:
        line = file_out.stdout.readline()
        print(line.decode('utf-8').strip('\r\n'))
        if subprocess.Popen.poll(file_out) == 0:
            break
        if not line.decode('utf-8').strip('\r\n'):
            break_count += 1
        else:
            break_count = 0
        if break_count >= 10:
            break


def export_sql_file():
    MYSQL_INFO = {
        "DB": "db_name",
        "HOST": "127.0.0.1",
        "PORT": "3306",
        "USER": "root",
        "PASSWORD": "",
    }
    dump_dir = os.path.expanduser("~/Desktop/export_sql_dir")
    password_cmd = ""
    if MYSQL_INFO['PASSWORD']:
        password_cmd = f"-p'{MYSQL_INFO['PASSWORD']}'"
    index_count = 0
    for table_name in ALL_TABLES[index_count:]:
    	# --column-statistics=0 当使用高版本mysqldump访问低版本mysql时需要加的参数
    	# --default-character-set=utf8 虽然mysqldump说明里写到默认编码就是utf8但是实际使用中发现不加的话，导出的中文全部为？
    	# --single-transaction --no-tablespaces 实际工作用由于给你使用的账号100%不是root账号，有些权限时没有的，当没有锁表权限时，需要加这2个参数
        dump_cmd = f"mysqldump --column-statistics=0 -u{MYSQL_INFO['USER']} -P {MYSQL_INFO['PORT']} {password_cmd} -h {MYSQL_INFO['HOST']} --default-character-set=utf8 -t {MYSQL_INFO['DB']} --single-transaction --no-tablespaces "
        print(f"-------------export {table_name} ------------- index of ALL_TABLES: {index_count}")
        dump_cmd += f"--tables {table_name} --where='id=1000000000' > {dump_dir}/{table_name}.sql"
        {dump_dir}/{table_name}.sql"
        print(dump_cmd)
        index_count += 1
        subprocess_popen(dump_cmd)
        print("")
        # exit()


def import_by_file():
    MYSQL_INFO = {
        "DB": "db_name",
        "HOST": "127.0.0.1",
        "PORT": "3306",
        "USER": "root",
        "PASSWORD": "",
    }
    dump_dir = os.path.expanduser("~/Desktop/export_sql_dir")
    index_count = 0
    for table_name in ALL_TABLES[index_count:]:
        print(f"-------------import {table_name} ------------- index of ALL_TABLES: {index_count}")
        import_cmd = f"mysql -u{MYSQL_INFO['USER']} -P{MYSQL_INFO['PORT']} -p{MYSQL_INFO['PASSWORD']} -h {MYSQL_INFO['HOST']} {MYSQL_INFO['DB']} < {dump_dir}/{table_name}.sql"
        subprocess_popen(import_cmd)
        print(import_cmd)
        print("")
        index_count += 1


def truncate_table():
	# 这是清空表的函数（谨慎使用）怕有人误用，我把里面执行sql的部分注释了，如果要使用打开就好
    MYSQL_INFO = {
        "DB": "db_name",
        "HOST": "127.0.0.1",
        "PORT": "3306",
        "USER": "root",
        "PASSWORD": "",
    }
    connection = pymysql.connect(host=MYSQL_INFO['HOST'],
                                 user=MYSQL_INFO['USER'],
                                 password=MYSQL_INFO['PASSWORD'],
                                 database=MYSQL_INFO['DB'],
                                 port=int(MYSQL_INFO['PORT']),
                                 cursorclass=pymysql.cursors.DictCursor)

    with connection:
        with connection.cursor() as cursor:
            index_count = 0
            for table_name in ALL_TABLES[index_count:]:
                print(f"-------------truncate {table_name} ------------- index of ALL_TABLES: {index_count}")
                sql = f"TRUNCATE TABLE {table_name}"
                print(sql)
                # cursor.execute(sql)
                print("")
                index_count += 1


if __name__ == '__main__':
    export_sql_file()
    # truncate_table()
    # import_by_file()