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Quelles sont les bases de données courantes en python ?

爱喝马黛茶的安东尼
爱喝马黛茶的安东尼original
2019-06-12 11:11:539607parcourir

Quelles sont les bases de données courantes en python ? Les bases de données sont grossièrement divisées en deux catégories. La première catégorie comprend les bases de données relationnelles et la deuxième catégorie est constituée des bases de données non relationnelles. Ce qui suit est une introduction aux connaissances pertinentes de ces deux types de bases de données.

Y compris les bases de données relationnelles : sqlite, mysql, mssql

Bases de données non relationnelles : MongoDB, Redis

Quelles sont les bases de données courantes en python ?

1. à SQLite

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. Connectez MySQL

Recommandations associées : "tutoriel vidéo Python"

2.2 Utilisation de MySQLdb

2.1 Utilisation de _mysql dans la bibliothèque mysqldb

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 Utilisation MySQLdb

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 Utilisez pymysql

Les sections 2.1 et 2.2 utilisent MySQLdb, qui ne prend pas en charge Python3.x
pymysql prend mieux en charge Python2.x et Python3.x

import pymysql
from contextlib import closing
import traceback
try:
    # 获取一个数据库连接,with关键字 表示退出时,conn自动关闭
    # with 嵌套上一层的with 要使用closing()
    with closing(pymysql.connect(host='localhost', user='root', passwd='root', db='test', port=3306,
                                 charset='utf8')) as conn:
        print("connect database successfully")
        # 获取游标,with关键字 表示退出时,cur自动关闭
        with 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 pymysql.Error as e:
    print("Mysql Error:", e)
    traceback.print_exc()

3. Connectez-vous à mssql

import pymssql
from contextlib import closing
try:
    # 先要保证数据库中有test数据库
    # 获取一个数据库连接,with关键字 表示退出时,conn自动关闭
    # with 嵌套上一层的with 要使用closing()
    with closing(pymssql.connect(host='192.168.100.114', user='sa', password='sa12345', database='test', port=1433,
                                 charset='utf8')) as conn:
        print("connect database successfully")
        # 获取游标,with关键字 表示退出时,cur自动关闭
        with conn.cursor() as cur:
            # 删除表
            cur.execute(
                    '''if exists (select 1 from  sys.objects where name='COMPANY' and  type='U')  drop table COMPANY''')
            # 创建表
            sql = """
                     CREATE TABLE  COMPANY
                   (ID INT  IDENTITY(1,1) PRIMARY KEY NOT NULL ,
                   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 pymssql.Error as e:
    print("mssql Error:", e)
    # traceback.print_exc()

4. Connectez-vous à MongoDB

import pymongo
from pymongo.mongo_client import MongoClient
import pymongo.errors
import traceback
try:
    # 连接到 mongodb 服务
    mongoClient = MongoClient('localhost', 27017)
    # 连接到数据库
    mongoDatabase = mongoClient.test
    print("connect database successfully")
    # 获取集合
    mongoCollection = mongoDatabase.COMPANY
    # 移除所有数据
    mongoCollection.remove()
    # 添加数据
    mongoCollection.insert_many([{"Name": "Paul", "Age": "32", "Address": "California", "Salary": "20000.00"},
                                 {"Name": "Allen", "Age": "25", "Address": "Texas", "Salary": "15000.00"},
                                 {"Name": "Teddy", "Age": "23", "Address": "Norway", "Salary": "20000.00"},
                                 {"Name": "Mark", "Age": "25", "Address": "Rich-Mond", "Salary": "65000.00"},
                                 {"Name": "David", "Age": "27", "Address": "Texas", "Salary": "85000.00"},
                                 {"Name": "Kim", "Age": "22", "Address": "South-Hall", "Salary": "45000.00"},
                                 {"Name": "James", "Age": "24", "Address": "Houston", "Salary": "10000.00"}, ])
    #获取集合中的值
    for row in mongoCollection.find():
        print("-" * 50)  # 输出50个-,作为分界线
        print("%-10s %s" % ("_id", row['_id']))  # 字段名固定10位宽度,并且左对齐
        print("%-10s %s" % ("name", row['Name']))
        print("%-10s %s" % ("age", row['Age']))
        print("%-10s %s" % ("address", row['Address']))
        print("%-10s %s" % ("salary", row['Salary']))
    print('\n\n\n')
    # 使id自增
    mongoCollection.remove()
    # 创建计数表
    mongoDatabase.counters.save({"_id": "people_id", "sequence_value": 0})
    # 创建存储过程
    mongoDatabase.system_js.getSequenceValue = '''function getSequenceValue(sequenceName){
            var sequenceDocument = db.counters.findAndModify({
                query: {_id: sequenceName},
                update: {$inc:{sequence_value: 1}},
                new:true
            });
            return sequenceDocument.sequence_value;
        }'''
    mongoCollection.insert_many(
            [{"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "Paul", "Age": "32",
              "Address": "California", "Salary": "20000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "Allen", "Age": "25",
              "Address": "Texas", "Salary": "15000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "Teddy", "Age": "23",
              "Address": "Norway", "Salary": "20000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "Mark", "Age": "25",
              "Address": "Rich-Mond", "Salary": "65000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "David", "Age": "27",
              "Address": "Texas", "Salary": "85000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "Kim", "Age": "22",
              "Address": "South-Hall", "Salary": "45000.00"},
             {"_id": mongoDatabase.eval("getSequenceValue('people_id')"), "Name": "James", "Age": "24",
              "Address": "Houston", "Salary": "10000.00"}, ])
    for row in mongoCollection.find():
        print("-" * 50)  # 输出50个-,作为分界线
        print("%-10s %s" % ("_id", int(row['_id'])))  # 字段名固定10位宽度,并且左对齐
        print("%-10s %s" % ("name", row['Name']))
        print("%-10s %s" % ("age", row['Age']))
        print("%-10s %s" % ("address", row['Address']))
        print("%-10s %s" % ("salary", row['Salary']))
except pymongo.errors.PyMongoError as e:
    print("mongo Error:", e)
    traceback.print_exc()

5. Redis

5.1 Utilisation de redis

import redis
r = redis.Redis(host='localhost', port=6379, db=0, password="12345")
print("connect", r.ping())
# 看信息
info = r.info()
# or 查看部分信息
# info = r.info("Server")
# 输出信息
items = info.items()
for i, (key, value) in enumerate(items):
    print("item %s----%s:%s" % (i, key, value))
# 删除键和对应的值
r.delete("company")
# 可以一次性push一条或多条数据
r.rpush("company", {"id": 1, "Name": "Paul", "Age": "32", "Address": "California", "Salary": "20000.00"},
        {"id": 2, "Name": "Allen", "Age": "25", "Address": "Texas", "Salary": "15000.00"},
        {"id": 3, "Name": "Teddy", "Age": "23", "Address": "Norway", "Salary": "20000.00"})
r.rpush("company", {"id": 4, "Name": "Mark", "Age": "25", "Address": "Rich-Mond", "Salary": "65000.00"})
r.rpush("company", {"id": 5, "Name": "David", "Age": "27", "Address": "Texas", "Salary": "85000.00"})
r.rpush("company", {"id": 6, "Name": "Kim", "Age": "22", "Address": "South-Hall", "Salary": "45000.00"})
r.rpush("company", {"id": 7, "Name": "James", "Age": "24", "Address": "Houston", "Salary": "10000.00"})
# eval用来将dict格式的字符串转换成dict
for row in map(lambda x: eval(x), r.lrange("company", 0, r.llen("company"))):
    print("-" * 50)  # 输出50个-,作为分界线
    print("%-10s %s" % ("_id", row['id']))  # 字段名固定10位宽度,并且左对齐
    print("%-10s %s" % ("name", row['Name']))
    print("%-10s %s" % ("age", row['Age']))
    print("%-10s %s" % ("address", row['Address']))
    print("%-10s %s" % ("salary", row['Salary']))
# 关闭当前连接
# r.shutdown() #这个是关闭redis服务端

5.2 Utilisation de pyredis

import pyredis
r = pyredis.Client(host='localhost', port=6379, database=0, password="12345")
print("connect", r.ping().decode("utf-8"))
# 看信息
# info = r.execute("info").decode()
# or 查看部分信息
info = r.execute("info", "Server").decode()
# 输出信息
print(info)
# 删除键和对应的值
r.delete("company")
# 可以一次性push一条或多条数据
r.rpush("company", '''{"id": 1, "Name": "Paul", "Age": "32", "Address": "California", "Salary": "20000.00"}''',
        '''{"id": 2, "Name": "Allen", "Age": "25", "Address": "Texas", "Salary": "15000.00"}''',
        '''{"id": 3, "Name": "Teddy", "Age": "23", "Address": "Norway", "Salary": "20000.00"}''')
r.rpush("company", '''{"id": 4, "Name": "Mark", "Age": "25", "Address": "Rich-Mond", "Salary": "65000.00"}''')
r.rpush("company", '''{"id": 5, "Name": "David", "Age": "27", "Address": "Texas", "Salary": "85000.00"}''')
r.rpush("company", '''{"id": 6, "Name": "Kim", "Age": "22", "Address": "South-Hall", "Salary": "45000.00"}''')
r.rpush("company", '''{"id": 7, "Name": "James", "Age": "24", "Address": "Houston", "Salary": "10000.00"}''')
# eval用来将dict格式的字符串转换成dict
for row in map(lambda x: eval(x), r.lrange("company", 0, r.llen("company"))):
    print("-" * 50)  # 输出50个-,作为分界线
    print("%-10s %s" % ("_id", row['id']))  # 字段名固定10位宽度,并且左对齐
    print("%-10s %s" % ("name", row['Name']))
    print("%-10s %s" % ("age", row['Age']))
    print("%-10s %s" % ("address", row['Address']))
    print("%-10s %s" % ("salary", row['Salary']))
# 关闭当前连接
r.close()

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