mysql数据库表空间使用了多少怎么查

SELECT table_schema AS "数据库",
       ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS "大小(MB)"
FROM information_schema.tables
GROUP BY table_schema;

+--------------------+------------+
| 数据库             | 大小(MB)   |
+--------------------+------------+
| database1          | 100.50     |
| database2          | 200.75     |
| database3          | 50.25      |
+--------------------+------------+

SELECT table_name AS "表",
       ROUND((data_length + index_length) / 1024 / 1024, 2) AS "大小(MB)"
FROM information_schema.tables
WHERE table_schema = 'database1'
GROUP BY table_name;