【数据库】MySQL中数据库和表容量大小的查询方法以及Python实现

一、查看所有数据库容量大小

select
table_schema as '数据库',
sum(table_rows) as '记录数',
sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',
sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'
from information_schema.tables
group by table_schema
order by sum(data_length) desc, sum(index_length) desc;

二、查看(指定库)mysql库各表容量大小

select
table_schema as '数据库',
table_name as '表名',
table_rows as '记录数',
truncate(data_length/1024/1024, 2) as '数据容量(MB)',
truncate(index_length/1024/1024, 2) as '索引容量(MB)'
from information_schema.tables
where table_schema='mysql'
order by data_length desc, index_length desc;

三、查看所有数据库各表容量大小

select
table_schema as '数据库',
table_name as '表名',
table_rows as '记录数',
truncate(data_length/1024/1024, 2) as '数据容量(MB)',
truncate(index_length/1024/1024, 2) as '索引容量(MB)'
from information_schema.tables
order by data_length desc, index_length desc

四、查看(指定库)mysql库各表容量大小

select
table_schema as '数据库',
table_name as '表名',
table_rows as '记录数',
truncate(data_length/1024/1024, 2) as '数据容量(MB)',
truncate(index_length/1024/1024, 2) as '索引容量(MB)'
from information_schema.tables
where table_schema='mysql'
order by data_length desc, index_length desc;

五、在Python中实现

import MySQLdb


# 连接管理
class Client():
    def __init__(self, **kwargs):
        try:
            self.conn = MySQLdb.connect(host=kwargs.get('host'),
                                        user=kwargs.get('user', 'root'),
                                        password=kwargs.get('password'),
                                        charset=kwargs.get('charset', 'utf8'),
                                        use_unicode=kwargs.get('use_unicode', True))
            self.cursor = self.conn.cursor()
            print("\nMySQL连接成功!\n")
            if kwargs.get('db'):
                self.SetDatabase(kwargs.get('db'))
        except Exception as errMsg:
            raise Exception(errMsg)

    # ---------------------------------------------------------------------------------------------------
    def SetDatabase(self, db):
        try:
            self.cursor.execute('USE {0}'.format(db))  # 设置（修改）当前数据库
            print("\n已连接数据库{0}\n".format(db))
        except Exception as e:
            print(e)

    def CloseConnection(self):
        # 关闭数据库连接
        self.conn.close()
        print("\nMySQL连接已关闭!\n")


class MysqlPython(Client):
    def __init__(self, **kwargs):
        Client.__init__(self, db=kwargs.get('db', 'testdb'), host=kwargs.get('host', 'localhost'),
                        password=kwargs.get('password', '123'))
        self.COMMIT_THRESHOLD = 10000

    def DescDatabases(self):
        """查看所有数据库容量大小"""
        sql = """select
            table_schema,
            sum(table_rows) as '记录数',
            sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',
            sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'
            from information_schema.tables
            group by table_schema
            order by sum(data_length) desc, sum(index_length) desc
        """
        self.cursor.execute(sql)
        info = self.cursor.fetchall()
        return info

    def DescDatabase(self, db):
        """查看(指定库)mysql库容量大小"""

        sql = """select
            table_schema as '数据库',
            sum(table_rows) as '记录数',
            sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',
            sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'
            from information_schema.tables
            where table_schema='{0}';
        """.format(db)
        self.cursor.execute(sql)
        info = self.cursor.fetchall()
        return info

    def DescDbsTables(self):
        """查看所有数据库各表容量大小"""
        sql = """select
            table_schema as '数据库',
            table_name as '表名',
            table_rows as '记录数',
            truncate(data_length/1024/1024, 2) as '数据容量(MB)',
            truncate(index_length/1024/1024, 2) as '索引容量(MB)'
            from information_schema.tables
            order by data_length desc, index_length desc
        """
        self.cursor.execute(sql)
        info = self.cursor.fetchall()
        return info

    def DescDbTables(self, db):
        """查看(指定库)各表容量大小"""
        sql = """select
            table_schema as '数据库',
            table_name as '表名',
            table_rows as '记录数',
            truncate(data_length/1024/1024, 2) as '数据容量(MB)',
            truncate(index_length/1024/1024, 2) as '索引容量(MB)'
            from information_schema.tables
            where table_schema='{0}'
            order by data_length desc, index_length desc;
        """.format(db)
        self.cursor.execute(sql)
        info = self.cursor.fetchall()
        return info


if __name__ == '__main__':
    client = MysqlPython()
    print(client.DescDatabases())
    print(client.DescDatabase(db='mysql'))
    print(client.DescDbsTables())
    print(client.DescDbTables(db='mysql'))

参考
https://baijiahao.baidu.com/s?id=1645704003578890261&wfr=spider&for=pc