将Python字典用于SQL

在这篇文章中，我们将探讨如何将Python字典用于SQL。我们将会从以下几个方面进行阐述：

一、字典和SQL的基本概念

1、字典的定义和用途

dict = {"name": "John", "age": 30, "city": "New York"}

2、SQL的定义和用途

SELECT * FROM table_name WHERE condition;

二、将字典插入到SQL数据库

1、使用Python的DB API插入字典到SQL数据库

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="username",
  password="password",
  database="database_name"
)

mycursor = mydb.cursor()

sql = "INSERT INTO table_name (name, age, city) VALUES (%s, %s, %s)"
val = (dict["name"], dict["age"], dict["city"])

mycursor.execute(sql, val)

mydb.commit()

2、使用SQLAlchemy将字典插入到SQL数据库

from sqlalchemy import create_engine, Column, String, Integer
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

class User(Base):
    __tablename__ = 'table_name'
    id = Column(Integer, primary_key=True)
    name = Column(String(50))
    age = Column(Integer)
    city = Column(String(50))

# 创建数据库连接
engine = create_engine('mysql+pymysql://username:password@localhost/database_name')
Session = sessionmaker(bind=engine)
session = Session()

# 创建字典对象
user = User(name=dict["name"], age=dict["age"], city=dict["city"])

# 插入字典对象到数据库
session.add(user)
session.commit()

三、将SQL结果转换为字典

1、使用Python的DB API将SQL结果转换为字典

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="username",
  password="password",
  database="database_name"
)

mycursor = mydb.cursor()

mycursor.execute("SELECT * FROM table_name")

result = mycursor.fetchall()

dict_list = []
for row in result:
    dict = {"name": row[0], "age": row[1], "city": row[2]}
    dict_list.append(dict)

2、使用SQLAlchemy将SQL结果转换为字典

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

# 创建数据库连接
engine = create_engine('mysql+pymysql://username:password@localhost/database_name')
Session = sessionmaker(bind=engine)
session = Session()

# 查询数据库
result = session.execute("SELECT * FROM table_name")

dict_list = []
for row in result:
    dict = {"name": row[0], "age": row[1], "city": row[2]}
    dict_list.append(dict)

四、总结

通过本文，我们了解到了如何将Python字典用于SQL。我们学习了如何将字典插入到SQL数据库中以及如何将SQL结果转换为字典。这将使我们在使用Python和SQL时更加灵活和方便。