Python之csv文件从MySQL数据库导入导出

Python从MySQL数据库中导出csv文件处理

csv文件导入MySQL数据库

import pymysqlimport csvimport codecsdef get_conn():    conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='root', db='test_csv', charset='utf8')    return conndef insert(cur, sql, args):    cur.execute(sql, args)def read_csv_to_mysql(filename):    with codecs.open(filename=filename, mode='r', encoding='utf-8') as f:        reader = csv.reader(f)        head = next(reader)        conn = get_conn()        cur = conn.cursor()        sql = 'insert into tb_csv values(%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)'        for item in reader:            if item[1] is None or item[1] == '':  # item[1]作为唯一键，不能为null                continue            args = tuple(item)            print(args)            insert(cur, sql=sql, args=args)        conn.commit()        cur.close()        conn.close()if __name__ == '__main__':    read_csv_to_mysql('1.csv')

注：

• 1.csv文件的表头如：

序号,合同编号,义务人,档案柜号,柜内编号,权利人,放款金额,放款日期,他项权利证编号,抵押物地址,结清出库日期,备注,地区

• mysql的创建tb_csv表语句

CREATE TABLE tb_csv(    xuhao VARCHAR(20),    htcode VARCHAR(20),    yiwuren VARCHAR(20),    dagh VARCHAR(20),    gncode VARCHAR(20),    quanliren VARCHAR(20),    fkmoney VARCHAR(20),    fkdata VARCHAR(20),    qitacode VARCHAR(20),    diyaaddr VARCHAR(100),    jqdata VARCHAR(30),    beizhu  VARCHAR(30),    zone    VARCHAR(30),    PRIMARY KEY(htcode))CHARSET=utf8;

这里为了省事，表中的字段都指明varchar类型

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MySQL数据库写入csv文件

import pymysqlimport csvimport codecsdef get_conn():    conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='root', db='test_csv', charset='utf8')    return conndef query_all(cur, sql, args):    cur.execute(sql, args)    return cur.fetchall()def read_mysql_to_csv(filename):    with codecs.open(filename=filename, mode='w', encoding='utf-8') as f:        write = csv.writer(f, dialect='excel')        conn = get_conn()        cur = conn.cursor()        sql = 'select * from tb_csv'        results = query_all(cur=cur, sql=sql, args=None)        for result in results:            print(result)            write.writerow(result)if __name__ == '__main__':    read_mysql_to_csv('2.csv')