1、
查询数据库的某一张表
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# 查询数据库的某一张表
import MySQLdb
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
db = MySQLdb.connect("localhost", "root", "dong2025", "mysql8", charset='utf8')
# 使用cursor()方法获取操作游标
cursor = db.cursor()
# SQL 查询数据库中的某一张表
sql = "SELECT * FROM BOOK WHERE BOOK_ID > 3"
# 执行sql语句
cursor.execute(sql)
# fetchall():接收全部的返回结果行.
# alldata = cursor.fetchall()
# return alldata
# fetchone(): 该方法获取下一个查询结果集。结果集是一个对象
onedate = cursor.fetchone()
return onedate
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
my_con = mysql_conn()
print(my_con)
2、
SQL 插入语句
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# SQL 插入语句
import MySQLdb
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
db = MySQLdb.connect("localhost", "root", "dong2025", "mysql8", charset='utf8')
# 使用cursor()方法获取操作游标
cursor = db.cursor()
# SQL 插入语句
sql = """
INSERT INTO BOOK(book_id, SORT, book_name, writer, OUTPUT, price)
VALUES (11, 'T8988', '数据科学家', '作者_李克强', '深圳出版社', 666.00)
"""
# 执行sql语句
cursor.execute(sql)
# 提交到数据库执行
db.commit()
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
mysql_conn()
3、
SQL update更新语句
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# SQL update更新语句
import MySQLdb
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
db = MySQLdb.connect("localhost", "root", "dong2025", "mysql8", charset='utf8')
# 使用cursor()方法获取操作游标
cursor = db.cursor()
# SQL update更新语句
sql = "UPDATE BOOK SET book_name = 'python算法导论' WHERE book_id= 9"
print(sql)
# 执行sql语句
cursor.execute(sql)
# 提交到数据库执行
db.commit()
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
mysql_conn()
4、
SQL 删除语句
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# SQL 删除语句
import MySQLdb
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
db = MySQLdb.connect("localhost", "root", "dong2025", "mysql8", charset='utf8')
# 使用cursor()方法获取操作游标
cursor = db.cursor()
# SQL delete语句
str_num = 8
sql = F"DELETE FROM BOOK WHERE book_id= {str_num}"
print(sql)
# 执行sql语句
cursor.execute(sql)
# 提交到数据库执行
db.commit()
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
mysql_conn()
5、
# cursorclass=pymysql.cursors.DictCursor
# 与
# cursor=pymysql.cursors.DictCursor
# 的用法及区别
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# 查询数据库的某一张表
# cursorclass=pymysql.cursors.DictCursor
# 与
# cursor=pymysql.cursors.DictCursor
# 的用法及区别
import pymysql
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
# db = pymysql.connect("localhost", "root", "dong2025", "mysql8", charset='utf8')
db = pymysql.connect(
host="localhost",
port=3306,
user="root",
password="dong2025",
database="mysql8",
charset="utf8",
# cursorclass=pymysql.cursors.DictCursor # 可以返回字典数据(包含字段名字),
)
# 使用cursor()方法获取操作游标
# cursor = db.cursor()
cursor = db.cursor(cursor=pymysql.cursors.DictCursor) # 可以返回字典数据(包含字段名字)
# SQL 查询数据库中的某一张表
sql = "SELECT * FROM BOOK WHERE BOOK_ID > 3"
# 执行sql语句
cursor.execute(sql)
# fetchall():接收全部的返回结果行.
# alldata = cursor.fetchall()
# return alldata
# fetchone(): 该方法获取下一个查询结果集。结果集是一个对象
onedate = cursor.fetchone()
return onedate
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
my_con = mysql_conn()
print(my_con)
5.1,pymysql,pandas,mysql一起来操作数据库
import pandas as pd
import pymysql
db = ""
def mysql_conn():
global db
try:
# 打开数据库连接
db = pymysql.connect(
host="localhost",
port=3306,
user="root",
password="dong2025",
database="mysql8",
charset="utf8",
)
sql = "SELECT * FROM BOOK"
df_sql = pd.read_sql(sql, db)
# return df_sql # 展示所有结果
# return df_sql.head() # 默认展示前5行
# return df_sql.head(2) # 展示前2行
# return df_sql.shape # 统计行和列数。
return df_sql.info() # info()方法可以查看数据表中的数据类型
except:
# Rollback in case there is any error
db.rollback()
finally:
db.close()
my_con = mysql_conn()
print(my_con)
7、Python连接MySQL数据库方法介绍(超详细!手把手项目案例操作) - 哔哩哔哩https://www.bilibili.com/read/cv3418619
8、Python3下不同MySQL驱动的性能对比_Python小屋-CSDN博客
9、
mysql客户端pymysql在python下性能比较_得救之道就在其中-CSDN博客
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