Useful MySQL Commands

This is an article dedicated to useful SQL commands to run in PHPmyAdmin or via Heidi/SQLYog. They serve various purposes and hopefully come in handy.

Get Total DB Size

Use this query as is in PHPmyAdmin to get a total size of all databases accessible.

SELECT table_schema "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema;

Display Table Names Sorted by Size

Remember to replace DATABASENAME with the name of the database. This will return a list of all tables in the database sorted from largest use to smallest in MB.

SELECT table_name AS "Table",
ROUND(((data_length + index_length) / 1024 / 1024), 2) AS "Size (MB)"
FROM information_schema.TABLES
WHERE table_schema = "DATABASENAME"
ORDER BY (data_length + index_length) DESC;