Python操作数据库增删查改
作者:互联网
import pymysql def opop1(): """ 创建一个表 :return: """ try: db = pymysql.connect(host="localhost", user="root", password="root", database="lzy",charset="utf8") #host 链接本机 user账户 password密码 database索要打开的库 charestUTF8 print("数据库链接成功!") cursor = db.cursor() #使用cursor()方法创建一个游标 cursor.execute("DROP TABLE IF EXISTS booksss") #使用execute()方法执行SQL,如果表存在则删除 sql = """ CREATE TABLE booksss( 编号 int(8) NOT NULL, 书名 varchar (50) NOT NULL, 作者 varchar (50) NOT NULL, 价格 decimal(10,2) DEFAULT NULL, 出版日期 date DEFAULT NULL ) """ #使用预处理语句创建表 cursor.execute(sql) #执行sql语句 db.close() #关闭数据库 except pymysql.Error as e: print("数据库链接失败:"+str(e)) def opop2(): """ 向表里插入信息 :return: """ try: db = pymysql.connect(host="localhost", user="root", password="root", database="lzy",charset="utf8") #host 链接本机 user账户 password密码 database索要打开的库 charestUTF8 print("数据库链接成功!") cursor = db.cursor() #使用cursor()方法创建一个游标 data = [("1","《红楼梦》","曹雪芹","810","1990-1-5"), ("2","《三国演义》","罗贯中","820","1990-6-5"), ("3","《西游记》","吴承恩","801","1990-5-5"), ("4","《水浒传》","施耐庵","803","1990-4-5"), ("5","《神雕侠侣》","金庸","840","1990-2-5") ] try: cursor.executemany("insert into booksss(编号,书名,作者,价格,出版日期)values (%s,%s,%s,%s,%s)",data) #执行sql语句,插入多条数据 db.commit() #提交数据 except : db.rollback() #发生错误时回滚 db.close() #关闭数据库连接 except pymysql.Error as e: print("数据库链接失败:"+str(e)) def opop3(): """ 查询数据 :return: """ db = pymysql.connect(host="localhost", user="root", password="root", database="lzy", charset="utf8") # host 链接本机 user账户 password密码 database索要打开的库 charestUTF8 print("数据库链接成功!") cursor = db.cursor() # 使用cursor()方法创建一个游标 cursor.execute("select * from booksss;") while 1: res = cursor.fetchone() if res is None: # 表示已经取完结果集 break print(res) cursor.close() db.commit() db.close() print('sql执行成功') def opop4(): """ 删除数据 :return: """ db = pymysql.connect(host="localhost", user="root", password="root", database="lzy", charset="utf8") # host 链接本机 user账户 password密码 database索要打开的库 charestUTF8 print("数据库链接成功!") cursor = db.cursor() # 删除前查询所有数据 cursor.execute("select * from booksss;") print('删除前的数据为:') for res in cursor.fetchall(): print(res) print('*' * 40) # 删除1条数据 sql = "delete from booksss where 作者 like '施耐庵';" cursor.execute(sql) # 删除后查询所有数据 cursor.execute("select * from booksss;") print('删除后的数据为:') for res in cursor.fetchall(): print(res) cursor.close() db.commit() db.close() print('sql执行成功') def opop5(): """ 修改数据 :return: """ db = pymysql.connect(host="localhost", user="root", password="root", database="lzy", charset="utf8") # host 链接本机 user账户 password密码 database索要打开的库 charestUTF8 print("数据库链接成功!") cursor = db.cursor() # 修改前查询所有数据 cursor.execute("select * from booksss;") print('修改前的数据为:') for res in cursor.fetchall(): print(res) print('*' * 40) # 更新表中第1条数据 cursor.execute("update booksss set 作者 = '李自扬' where 编号=3") # 修改后查询所有数据 cursor.execute("select * from booksss;") print('修改后的数据为:') for res in cursor.fetchall(): print(res) cursor.close() db.commit() db.close() print('sql执行成功') if __name__ == '__main__': opop5()
标签:execute,Python,res,db,cursor,print,查改,增删,password 来源: https://blog.csdn.net/weixin_56705224/article/details/122578379