一、概览
1、统计数据库信息
2、主要指标涉及： 数据表数量/字段总量/存储条数/存储量
二、命令
1、数据表数量
SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = '库名';
某个库中，有多少个表
~~2、字段总量
select
sum(FIELD_COUNT)
from
(
SELECT
TABLE_NAME,
COUNT(COLUMN_NAME) AS FIELD_COUNT
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_SCHEMA = '库名'
GROUP BY
TABLE_NAME
) t;
某个库，所有表的字段数累加
~~3、存储条数
select
sum(TABLE_ROWS)
from
(
SELECT
TABLE_NAME,
TABLE_ROWS
FROM
INFORMATION_SCHEMA.TABLES
WHERE
TABLE_SCHEMA = '库名'
) t;
所有表的记录条数
~~4、存储量
select
sum(mb)
from
(
SELECT
TABLE_SCHEMA AS "Database",
TABLE_NAME AS "Table",
round(((data_length + index_length) / 1024 / 1024), 2) as mb
FROM
INFORMATION_SCHEMA.TABLES
WHERE
TABLE_SCHEMA = '库名'
) t;
所有记录的磁盘占比，数据大小；参考值，非精确值
~~