MYSQL数据库巡检的代码

以下是一个简单的MySQL数据库巡检代码，可以检查数据库的基本信息和状态，如空间使用情况、连接数、缓存命中率等。

import mysql.connector

# 连接数据库
conn = mysql.connector.connect(
    host="localhost",
    user="myuser",
    password="mypassword",
    database="mydatabase"
)

# 获取数据库状态信息
cur = conn.cursor()
cur.execute("SELECT VERSION();")
db_version = cur.fetchone()
print("Database version: ", db_version)

# 检查空间使用情况
cur.execute("SELECT CONCAT(SUM(data_length + index_length) / 1024 / 1024, ' MB') AS size FROM information_schema.TABLES WHERE table_schema = 'mydatabase';")
db_size = cur.fetchone()[0]
print("Database size: ", db_size)

# 检查连接数
cur.execute("SHOW STATUS WHERE `variable_name` = 'Threads_connected';")
num_connections = cur.fetchone()[1]
print("Number of connections: ", num_connections)

# 检查缓存命中率
cur.execute("SHOW STATUS WHERE `variable_name` = 'Innodb_buffer_pool_reads';")
buffer_pool_reads = cur.fetchone()[1]
cur.execute("SHOW STATUS WHERE `variable_name` = 'Innodb_buffer_pool_read_requests';")
buffer_pool_read_requests = cur.fetchone()[1]
cache_hit_ratio = (1 - float(buffer_pool_reads) / float(buffer_pool_read_requests)) * 100
print("Cache hit ratio: ", cache_hit_ratio)

# 关闭连接
cur.close()
conn.close()

当然，这只是一个简单的示例，实际的数据库巡检代码需要根据具体的需求和数据库类型进行适当的修改和扩展。