Python中操作MySql
创建数据库表
【示例】创建表student
import pymysql db = pymysql.connect("localhost","root","root","python_db") # 创建游标对象 cursor=db.cursor() try: # 使用execute()方法执行sql，如果表存在则删除 cursor.execute("drop table if exists student") # 创建表 sql sql= ''' create table student( sno int(8) primary key auto_increment, sname char(30) not null, sex varchar(5), age int(2), score float(3,1) ) ''' cursor.execute(sql) print('创表成功') except Exception as e: print(e) print("创表失败") finally: db.close() 数据库插入操作
在Python程序中，可以使用SQL语句向数据库中插入新的数据信息。
【示例】向student表中插入数据信息
import pymysql db=pymysql.connect("localhost", "root", "root", 'python_db') cursor = db.cursor() sql= ''' insert into student(sname,sex,age,score) values(%s,%s,%s,%s) ''' try: cursor.execute(sql, ('李四', 'man', 25, 99.5)) # 提交事务 db.commit() print('插入成功') except Exception as e : print(e) # 如果出现异常，回滚 db.rollback() print("插入失败") finally: db.close() 【示例】向student表同时插入多条数据
import pymysql db = pymysql.connect("localhost", "root", "root", "python_db") cursor = db.cursor() sql=''' insert into student(sname, sex, age, score) values(%s,%s,%s,%s) ''' args = [("王五","man",23,80),("马二","woman",20,90)] try: cursor.executemany(sql,args) db.commit() print("插入成功") except Exception as e: print(e) print("插入失败") finally: db.close() 数据库查询操作
import pymysql db=pymysql.connect("localhost","root","root","python_db") cursor=db.cursor() sql = 'select * from student ' try: cursor.execute(sql) #获取结果 stus = cursor.fetchall() print(stus) for stu in stus: sno = stu[0] sname = stu[1] sex = stu[2] age = stu[3] score = stu[4] print("sno:",sno,"sname:",sname,"sex:",sex,"age:",age,'score:',score) except Exception as e: print(e) print("查询失败") finally: db.close() 数据库更新操作
在Python程序中，可以使用update语句更新数据库中数据信息。
import pymysql db = pymysql.connect("localhost","root","root","python_db") cursor = db.cursor() sql= 'update student set score=%s where sno=%s' try: cursor.execute(sql,(92,3)) db.commit() print("修改成功") except Exception as e : print("修改失败") print(e) db.rollback() finally: db.close() 数据库删除操作
在Python程序中，可以使用delete语句删除数据库中的数据信息
【示例】删除年龄小于25的学生
import pymysql db=pymysql.connect("localhost","root","root","python_db") cursor=db.cursor() sql = 'delete from student where age<25' try: cursor.execute(sql) db.commit() print('删除成功') except Exception as e: print(e) print("删除失败") finally: db.close() nt where age<25’
try:
cursor.execute(sql)
db.commit()
print(‘删除成功’)
except Exception as e:
print(e)
print(“删除失败”)
finally:
db.close()
文章来源: https://blog.csdn.net/weixin_44342108/article/details/96718602