一文掌握6种Python中常用数据库操作及代码

import pymysql

# 连接数据库
conn = pymysql.connect(host='localhost', user='root', password='123456', database='test')

# 创建游标对象
cursor = conn.cursor()

# 执行SQL语句
cursor.execute("SELECT * FROM students")

# 获取查询结果
result = cursor.fetchall()

# 打印结果
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

import sqlite3

# 连接数据库
conn = sqlite3.connect('test.db')

# 创建游标对象
cursor = conn.cursor()

# 执行SQL语句
cursor.execute("SELECT * FROM students")

# 获取查询结果
result = cursor.fetchall()

# 打印结果
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

import psycopg2

# 连接数据库
conn = psycopg2.connect(database="test", user="postgres", password="123456", host="localhost", port="5432")

# 创建游标对象
cursor = conn.cursor()

# 执行SQL语句
cursor.execute("SELECT * FROM students")

# 获取查询结果
result = cursor.fetchall()

# 打印结果
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

import cx_Oracle

# 连接数据库
conn = cx_Oracle.connect("username/password@localhost:1521/orcl")

# 创建游标对象
cursor = conn.cursor()

# 执行SQL语句
cursor.execute("SELECT * FROM students")

# 获取查询结果
result = cursor.fetchall()

# 打印结果
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

from pymongo import MongoClient

# 连接数据库
client = MongoClient('mongodb://localhost:27017/')

# 获取数据库
db = client['test']

# 获取集合
collection = db['students']

# 查询数据
result = collection.find()

# 打印结果
for doc in result:
    print(doc)

# 关闭连接
client.close()

import redis

# 连接数据库
r = redis.Redis(host='localhost', port=6379, db=0)

# 设置键值对
r.set('name', 'Tom')

# 获取键值对
value = r.get('name')

# 打印结果
print(value)

# 关闭连接
r.close()