MySQL 数据库保存代码示例

以下是一个简单的 MySQL 数据库保存代码示例,包括连接数据库、创建表、插入数据、查询数据等基本操作。
import mysql.connector
连接数据库
def connect_db():
try:
connection = mysql.connector.connect(
host='localhost',
user='your_username',
password='your_password',
database='your_database'
)
if connection.is_connected():
print("MySQL Connection is successful")
return connection
except mysql.connector.Error as e:
print("Error while connecting to MySQL", e)
return None
创建表
def create_table(connection):
cursor = connection.cursor()
create_table_query = """
CREATE TABLE IF NOT EXISTS employees (
id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(255) NOT NULL,
age INT NOT NULL,
department VARCHAR(255) NOT NULL
);
"""
try:
cursor.execute(create_table_query)
print("Table created successfully")
except mysql.connector.Error as e:
print("Failed to create table", e)
插入数据
def insert_data(connection, name, age, department):
cursor = connection.cursor()
insert_query = """
INSERT INTO employees (name, age, department)
VALUES (%s, %s, %s);
"""
try:
cursor.execute(insert_query, (name, age, department))
connection.commit()
print("Data inserted successfully")
except mysql.connector.Error as e:
print("Failed to insert data", e)
查询数据
def query_data(connection):
cursor = connection.cursor()
query = "SELECT * FROM employees;"
try:
cursor.execute(query)
results = cursor.fetchall()
for row in results:
print(row)
except mysql.connector.Error as e:
print("Failed to fetch data", e)
主程序
if __name__ == "__main__":
connection = connect_db()
if connection:
create_table(connection)
insert_data(connection, 'John Doe', 30, 'HR')
insert_data(connection, 'Jane Smith', 25, 'IT')
query_data(connection)
connection.close()
print("MySQL connection is closed")
代码说明:
1、连接数据库:connect_db 函数用于连接到 MySQL 数据库。

2、创建表:create_table 函数用于创建一个名为employees 的表,其中包含id、name、age 和department 字段。
3、插入数据:insert_data 函数用于向employees 表中插入新记录。
4、查询数据:query_data 函数用于查询employees 表中的所有记录。

5、主程序:在主程序中,首先连接到数据库,然后创建表,插入数据,查询数据,最后关闭数据库连接。
确保在运行此代码之前,你已经有一个运行中的 MySQL 数据库,并且已经替换了your_username、your_password 和your_database 为实际的数据库用户名、密码和数据库名称。