Getting the date/time of the last change to a MySQ

问题:

I'm working with MySQL and I would like to get the date/time of the very last change to any table within a database. Each of my tables has an auto updating '*_modified' timestamp so I could use this (* is a prefix).

The purpose of this is to work out if the data has changed at all since the date/time of the last database backup.

I was wondering is there an simpler way to do this using DESCRIBE or SHOW? I've searched and experimented, but found nothing yet.

Thanks for the help.

回答1:

SELECT update_time
FROM   information_schema.tables
WHERE  table_schema = 'dbName'
       AND table_name = 'tableName'

回答2:

I found this metod, from http://mysqladministrators.blogspot.it/2012/02/get-database-size.html

I'm not sure if it can help you, since i'm not so prepared in MySql

Get the database size, free space and last update

To get the current database size just by querying into your query browser or CLI from the INFORMATION_SCHEMA database in table TABLES.

SELECT table_schema "Data Base Name", 
sum( data_length + index_length ) / 1024 / 1024 "Data Base Size in MB" 
FROM information_schema.TABLES 
GROUP BY table_schema ;

Get the database free space

SELECT table_schema "Data Base Name", 
sum( data_length + index_length ) / 1024 / 1024 "Data Base Size in MB", 
sum( data_free )/ 1024 / 1024 "Free Space in MB" 
FROM information_schema.TABLES 
GROUP BY table_schema;

Get the database last update ordered by update time then by create time.

SELECT MAX(UPDATE_TIME), MAX(CREATE_TIME), TABLE_SCHEMA 
FROM `TABLES` 
GROUP BY TABLE_SCHEMA 
ORDER BY 1, 2;

回答3:

The accepted answer is great, but I think a better format in case it's not immediately apparent to a rookie would be:

SELECT table_name, update_time
FROM   information_schema.tables
WHERE  table_schema = 'myDBName'
order by update_time DESC

Since, we don't always know what table(s) have been touched, and this has the bonus of giving a clue as to what the activity was by showing the most-recently-updated tables.

回答4:

Simply, to get all tables under one database use this query

SELECT TABLE_NAME,CREATE_TIME,UPDATE_TIME
FROM   information_schema.tables
WHERE  table_schema = 'database_name'

That's all