mysql 项目demo

-- 检查用户名和密码是否正确
mysql -u username -p

-- 如果用户名和密码正确，检查用户权限
SHOW GRANTS FOR 'username'@'localhost';

-- 添加索引
ALTER TABLE table_name ADD INDEX index_name (column_name);

-- 优化查询语句
EXPLAIN SELECT * FROM table_name WHERE column_name = 'value';

-- 备份数据库
mysqldump -u username -p database_name > backup.sql

-- 恢复数据库
mysql -u username -p database_name < backup.sql

import mysql.connector

# 连接到MySQL数据库
mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword",
  database="yourdatabase"
)

# 创建游标对象
mycursor = mydb.cursor()

# 执行SQL查询
mycursor.execute("SELECT * FROM customers")

# 获取查询结果
myresult = mycursor.fetchall()

for x in myresult:
  print(x)