Python之csv文件从MySQL数据库导入导出

秒速五厘米 2022-06-07 13:08 341阅读 0赞

### Python从MySQL数据库中导出csv文件处理 ###

#### csv文件导入MySQL数据库 ####

import pymysql
    import csv
    import codecs
    
    
    def get_conn():
        conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='root', db='test_csv', charset='utf8')
        return conn
    
    
    def 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

--------------------

#### MySQL数据库写入csv文件 ####

import pymysql
    import csv
    import codecs
    
    
    def get_conn():
        conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='root', db='test_csv', charset='utf8')
        return conn
    
    def 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')