python 连接各类主流数据库的实例代码-木庄网络博客

本文整理自网络，侵删。

本篇博文主要介绍Python连接各种数据库的方法及简单使用

包括关系数据库：sqlite,mysql,mssql

非关系数据库：MongoDB,Redis

代码写的比较清楚，直接上代码

1.连接sqlite

# coding=utf-8
# http://www.runoob.com/sqlite/sqlite-python.html
import sqlite3
import traceback

try:
 # 如果表不存在,就创建
 with sqlite3.connect('test.db') as conn:

  print("Opened database successfully")

  # 删除表
  conn.execute("DROP TABLE IF EXISTS COMPANY")

  # 创建表
  sql = """
     CREATE TABLE IF NOT EXISTS COMPANY
    (ID INTEGER PRIMARY KEY  AUTOINCREMENT,
    NAME   TEXT NOT NULL,
    AGE   INT  NOT NULL,
    ADDRESS  CHAR(50),
    SALARY   REAL);
  """
  conn.execute(sql)

  print("create table successfully")

  # 添加数据
  conn.executemany("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES (?, ?, ?, ? )",
       [('Paul', 32, 'California', 20000.00),
       ('Allen', 25, 'Texas', 15000.00),
       ('Teddy', 23, 'Norway', 20000.00),
       ('Mark', 25, 'Rich-Mond ', 65000.00),
       ('David', 27, 'Texas', 85000.00),
       ('Kim', 22, 'South-Hall', 45000.00),
       ('James', 24, 'Houston', 10000.00)])
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ( 'Paul', 32, 'California', 20000.00 )")
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ('Allen', 25, 'Texas', 15000.00 )")
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ('Teddy', 23, 'Norway', 20000.00 )")
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ( 'Mark', 25, 'Rich-Mond ', 65000.00 )")
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ( 'David', 27, 'Texas', 85000.00 )");
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ( 'Kim', 22, 'South-Hall', 45000.00 )")
  #
  # conn.execute("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)\
  # VALUES ( 'James', 24, 'Houston', 10000.00 )")

  # 提交,否则重新运行程序时,表中无数据
  conn.commit()
  print("insert successfully")

  # 查询表
  sql = """
   select id,NAME,AGE,ADDRESS,SALARY FROM COMPANY
   """

  result = conn.execute(sql)

  for row in result:
   print("-" * 50) # 输出50个-,作为分界线
   print("%-10s %s" % ("id", row[0])) # 字段名固定10位宽度,并且左对齐
   print("%-10s %s" % ("name", row[1]))
   print("%-10s %s" % ("age", row[2]))
   print("%-10s %s" % ("address", row[3]))
   print("%-10s %.2f" % ("salary", row[4]))
   # or
   # print('{:10s} {:.2f}'.format("salary", row[4]))


except sqlite3.Error as e:
 print("sqlite3 Error:", e)
 traceback.print_exc()

2.连接mysql

2.1使用mysqldb库中的_mysql

#! /usr/bin/env python2.7
# coding=utf-8
# Created by xiaosanyu at 16/5/30

# mysqldb 只支持python2.7
# http://mysql-python.sourceforge.net/

import MySQLdb
from contextlib import closing
import traceback

try:
 # 获取一个数据库连接
 with closing(MySQLdb.connect(host='localhost', user='root', passwd='root', db='test', port=3306,charset='utf8')) as conn:
  print("connect database successfully")
  with closing(conn.cursor()) as cur:
   # 删除表
   cur.execute("DROP TABLE IF EXISTS COMPANY")
   # 创建表
   sql = """
      CREATE TABLE IF NOT EXISTS COMPANY
     (ID INTEGER PRIMARY KEY NOT NULL auto_increment,
     NAME   TEXT NOT NULL,
     AGE   INT  NOT NULL,
     ADDRESS  CHAR(50),
     SALARY   REAL);
   """
   cur.execute(sql)

   print("create table successfully")

   # 添加数据
   # 在一个conn.execute里面里面执行多个sql语句是非法的
   cur.executemany("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( %s, %s, %s, %s )",
       [('Paul', 32, 'California', 20000.00),
        ('Allen', 25, 'Texas', 15000.00),
        ('Teddy', 23, 'Norway', 20000.00),
        ('Mark', 25, 'Rich-Mond ', 65000.00),
        ('David', 27, 'Texas', 85000.00),
        ('Kim', 22, 'South-Hall', 45000.00),
        ('James', 24, 'Houston', 10000.00)])

   # 提交,否则重新运行程序时,表中无数据
   conn.commit()
   print("insert successfully")

   # 查询表
   sql = """
    select id,NAME,AGE,ADDRESS,SALARY FROM COMPANY
    """

   cur.execute(sql)

   for row in cur.fetchall():
    print("-" * 50) # 输出50个-,作为分界线
    print("%-10s %s" % ("id", row[0])) # 字段名固定10位宽度,并且左对齐
    print("%-10s %s" % ("name", row[1]))
    print("%-10s %s" % ("age", row[2]))
    print("%-10s %s" % ("address", row[3]))
    print("%-10s %s" % ("salary", row[4]))

except MySQLdb.Error as e:
 print("Mysql Error:", e)
 traceback.print_exc() # 打印错误栈信息

2.2 使用MySQLdb

#! /usr/bin/env python2.7
# coding=utf-8
# Created by xiaosanyu at 16/5/30

# mysqldb 只支持python2.7
# http://mysql-python.sourceforge.net/

import MySQLdb
from contextlib import closing
import traceback

try:
 # 获取一个数据库连接
 with closing(MySQLdb.connect(host='localhost', user='root', passwd='root', db='test', port=3306,charset='utf8')) as conn:
  print("connect database successfully")
  with closing(conn.cursor()) as cur:
   # 删除表
   cur.execute("DROP TABLE IF EXISTS COMPANY")
   # 创建表
   sql = """
      CREATE TABLE IF NOT EXISTS COMPANY
     (ID INTEGER PRIMARY KEY NOT NULL auto_increment,
     NAME   TEXT NOT NULL,
     AGE   INT  NOT NULL,
     ADDRESS  CHAR(50),
     SALARY   REAL);
   """
   cur.execute(sql)

   print("create table successfully")

   # 添加数据
   # 在一个conn.execute里面里面执行多个sql语句是非法的
   cur.executemany("INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY) VALUES ( %s, %s, %s, %s )",
       [('Paul', 32, 'California', 20000.00),
        ('Allen', 25, 'Texas', 15000.00),
        ('Teddy', 23, 'Norway', 20000.00),
        ('Mark', 25, 'Rich-Mond ', 65000.00),
        ('David', 27, 'Texas', 85000.00),
        ('Kim', 22, 'South-Hall', 45000.00),
        ('James', 24, 'Houston', 10000.00)])

   # 提交,否则重新运行程序时,表中无数据
   conn.commit()
   print("insert successfully")

   # 查询表
   sql = """
    select id,NAME,AGE,ADDRESS,SALARY FROM COMPANY
    """

   cur.execute(sql)

   for row in cur.fetchall():
    print("-" * 50) # 输出50个-,作为分界线
    print("%-10s %s" % ("id", row[0])) # 字段名固定10位宽度,并且左对齐
    print("%-10s %s" % ("name", row[1]))
    print("%-10s %s" % ("age", row[2]))
    print("%-10s %s" % ("address", row[3]))
    print("%-10s %s" % ("salary", row[4]))

except MySQLdb.Error as e:
 print("Mysql Error:", e)
 traceback.print_exc() # 打印错误栈信息

2.3使用pymysql

2.1和2.2节使用MySQLdb，不支持Python3.x

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