MySQL: Reporting Size Of All Tables

This is a query to report the number of rows and the estimated size of all the tables in a MySQL database:

SELECT 
  table_name, 
  table_rows, 
  ROUND(((data_length + index_length) / 1024 / 1024), 2) AS mb_size
FROM information_schema.tables
WHERE table_schema = 'maindb;

Results look like:

table_name                                  table_rows mb_size 
------------------------------------------- ---------- ------- 
mageplaza_seodashboard_noroute_report_issue 314314     37.56   
catalog_product_entity_int                  283244     28.92   
catalog_product_entity_varchar              259073     29.84   
amconnector_product_log_details             178848     6.02    
catalog_product_entity_decimal              135936     16.02   
shipperhq_quote_package_items               115552     11.03   
amconnector_product_log                     114400     767.00  
amconnector_productinventory_log_details    114264     3.52    

This is a very useful query as the majority of MySQL applications are poorly designed; they tend not to clean up after themseves.