【Python】连接常用数据库

Python 连接常用数据库

• Python 连接常用数据库
  • Mongodb
  • Azure SQL databases
  • MySQL

Mongodb

1. 安装pymongo包

   pip install pymongo
   

2. 插入数据

   from pymongo import MongoClient
   client = MongoClient("mongodb://localhost:27017/")
   
   # get or create database
   db = client["Demo"]
   
   # get or create collection
   col = db["customers"]
   
   # insert one record
   data = col.insert_one({
       "name": "wilson",
       "sex": 1,
       "address": "tian he",
       "created": datetime.now()
   })
   
   # close connection
   client.close()
   

3. 查询数据

   from pymongo import MongoClient
   client = MongoClient("mongodb://localhost:27017/")
   
   # get or create database
   db = client["Demo"]
   
   # get or create collection
   col = db["customers"]
   
   # find one
   data = col.find_one()
   print(data)
   
   # find all
   datas = col.find()
   
   for data in datas:
       print(data)
   

Azure SQL databases

1. 安装freetds驱动

   brew install freetds
   

2. 安装pymssql包

   pip install pymssql
   

3. 插入数据

   import pymssql
   conn = pymssql.connect(server='yourserver.database.windows.net', user='yourusername@yourserver', password='yourpassword', database='AdventureWorks')
   cursor = conn.cursor()
   cursor.execute("INSERT SalesLT.Product (Name, ProductNumber, StandardCost, ListPrice, SellStartDate) OUTPUT INSERTED.ProductID VALUES ('SQL Server Express', 'SQLEXPRESS', 0, 0, CURRENT_TIMESTAMP)")
   row = cursor.fetchone()
   while row:
       print "Inserted Product ID : " +str(row[0])
       row = cursor.fetchone()
   conn.commit()
   conn.close()
   

4. 查询数据

   import pymssql
   conn = pymssql.connect(server='yourserver.database.windows.net', user='yourusername@yourserver', password='yourpassword', database='AdventureWorks')
   cursor = conn.cursor()
   cursor.execute('SELECT c.CustomerID, c.CompanyName,COUNT(soh.SalesOrderID) AS OrderCount FROM SalesLT.Customer AS c LEFT OUTER JOIN SalesLT.SalesOrderHeader AS soh ON c.CustomerID = soh.CustomerID GROUP BY c.CustomerID, c.CompanyName ORDER BY OrderCount DESC;')
   row = cursor.fetchone()
   while row:
       print str(row[0]) + " " + str(row[1]) + " " + str(row[2])
       row = cursor.fetchone()
   

MySQL

1. 安装pymysql包

   pip install pymysql
   

2. 查询数据

   import pymysql
   
   conn = pymysql.connect(
       host='127.0.0.1', user='root', password='123456', database='demo'
   )
   
   cursor = conn.cursor()
   
   sql = 'SELECT * FROM customers LIMIT 5'
   
   cursor.execute(sql)
   
   result = cursor.fetchone()
   
   print(result)
   
   cursor.close()
   
   conn.close()
   

3. 插入数据

   import pymysql
   
   conn = pymysql.connect(
       host='127.0.0.1', user='root', password='123456', database='demo'
   )
   
   cursor = conn.cursor()
   
   sql = 'INSERT INTO customers(name,phone) VALUES(%s,%s)'
   val = ('Wilson', '1388888888')
   
   cursor.execute(sql, val)
   
   conn.commit()
   
   print(cursor.rowcount, " record inserted.")
   
   cursor.close()
   
   conn.close()