python中如何将数据存入mysql

在Python中将数据存入MySQL的方法有：使用MySQL Connector、使用SQLAlchemy、使用Pandas等。 推荐使用MySQL Connector，因为它是MySQL官方提供的接口，性能和兼容性较好。首先，我们需要安装必要的库并进行数据库连接，然后创建表结构，最后将数据插入到MySQL数据库中。下面将详细介绍这些步骤。

一、安装和配置MySQL Connector

要使用MySQL Connector，首先需要安装它。可以使用以下命令进行安装：

pip install mysql-connector-python

安装完成后，接下来需要配置MySQL数据库连接。

二、连接到MySQL数据库

在进行数据库操作前，需要先建立一个与MySQL数据库的连接。以下是一个连接MySQL数据库的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        db_Info = connection.get_server_info()
        print("Connected to MySQL Server version ", db_Info)
        cursor = connection.cursor()
        cursor.execute("select database();")
        record = cursor.fetchone()
        print("You're connected to database: ", record)
except Error as e:
    print("Error while connecting to MySQL", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

替换 'your_host'，'your_database'，'your_username' 和 'your_password' 为实际的数据库连接信息。执行该代码后，您应该能够看到连接成功的信息。

三、创建表结构

在将数据插入数据库之前，需要先创建一个表结构。以下是一个创建表的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        cursor = connection.cursor()
        cursor.execute("CREATE TABLE IF NOT EXISTS employees (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), salary FLOAT)")
        print("Table is created successfully")
except Error as e:
    print("Error while creating table", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

四、插入数据

创建表后，可以将数据插入到表中。以下是一个插入数据的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        cursor = connection.cursor()
        cursor.execute("INSERT INTO employees (name, salary) VALUES ('John Doe', 70000)")
        connection.commit()
        print(cursor.rowcount, "Record inserted successfully into employees table")
except Error as e:
    print("Failed to insert record into MySQL table", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

五、使用参数化查询插入数据

为了防止SQL注入攻击，推荐使用参数化查询来插入数据。以下是一个使用参数化查询插入数据的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        cursor = connection.cursor()
        sql_insert_query = """ INSERT INTO employees (name, salary) VALUES (%s,%s)"""
        insert_tuple = ("Jane Doe", 80000)
        cursor.execute(sql_insert_query, insert_tuple)
        connection.commit()
        print(cursor.rowcount, "Record inserted successfully into employees table")
except Error as e:
    print("Failed to insert record into MySQL table", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

六、批量插入数据

有时需要一次性插入多条记录，可以使用 executemany() 方法。以下是一个批量插入数据的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        cursor = connection.cursor()
        sql_insert_query = """ INSERT INTO employees (name, salary) VALUES (%s,%s)"""
        records_to_insert = [("Alice", 90000), ("Bob", 85000), ("Charlie", 95000)]
        cursor.executemany(sql_insert_query, records_to_insert)
        connection.commit()
        print(cursor.rowcount, "Records inserted successfully into employees table")
except Error as e:
    print("Failed to insert records into MySQL table", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

七、使用SQLAlchemy进行数据库操作

SQLAlchemy是一个功能强大的Python库，提供了ORM（对象关系映射）功能。以下是一个使用SQLAlchemy进行数据库操作的示例代码：

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, Float
from sqlalchemy.orm import sessionmaker
DATABASE_URL = "mysql+mysqlconnector://your_username:your_password@your_host/your_database"
engine = create_engine(DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()
class Employee(Base):
    __tablename__ = 'employees'
    id = Column(Integer, primary_key=True, index=True)
    name = Column(String(255), index=True)
    salary = Column(Float)
Base.metadata.create_all(bind=engine)
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()
def create_employee(db, name, salary):
    db_employee = Employee(name=name, salary=salary)
    db.add(db_employee)
    db.commit()
    db.refresh(db_employee)
    return db_employee
with get_db() as db:
    create_employee(db, "Dave", 75000)

使用SQLAlchemy可以更加方便地进行数据库操作，并且具有更高的代码可读性和可维护性。

八、使用Pandas将数据存入MySQL

Pandas是一个强大的数据处理库，结合SQLAlchemy可以方便地将数据存入MySQL。以下是一个使用Pandas将数据存入MySQL的示例代码：

import pandas as pd
from sqlalchemy import create_engine
DATABASE_URL = "mysql+mysqlconnector://your_username:your_password@your_host/your_database"
engine = create_engine(DATABASE_URL)
data = {
    'name': ['Eve', 'Frank', 'Grace'],
    'salary': [72000, 66000, 82000]
}
df = pd.DataFrame(data)
df.to_sql('employees', con=engine, if_exists='append', index=False)
print("Data inserted successfully into employees table")

九、错误处理和事务管理

在进行数据库操作时，错误处理和事务管理是非常重要的。以下是一个带有错误处理和事务管理的示例代码：

import mysql.connector
from mysql.connector import Error
try:
    connection = mysql.connector.connect(
        host='your_host',
        database='your_database',
        user='your_username',
        password='your_password'
    )
    if connection.is_connected():
        cursor = connection.cursor()
        cursor.execute("START TRANSACTION")
        cursor.execute("INSERT INTO employees (name, salary) VALUES ('Hank', 90000)")
        cursor.execute("INSERT INTO employees (name, salary) VALUES ('Ivy', 88000)")
        connection.commit()
        print(cursor.rowcount, "Records inserted successfully into employees table")
except Error as e:
    connection.rollback()
    print("Failed to insert records into MySQL table", e)
finally:
    if connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL connection is closed")

十、总结

在Python中将数据存入MySQL的方法有多种，推荐使用MySQL Connector、SQLAlchemy和Pandas。MySQL Connector是官方提供的接口，性能和兼容性较好；SQLAlchemy提供了ORM功能，代码可读性和可维护性更高；Pandas结合SQLAlchemy可以方便地处理和存储大量数据。在实际应用中，选择合适的方法可以提高开发效率和代码质量。