MySQL: How do I find out which tables reference a specific table?

Question

I want to drop a table but it is referenced by one or more other tables. How can I find out which tables are referencing this table without having to look at each of the tables in the database one by one?

Answer 1

Use Toad to load it up and you can view the references through the diagram. also make sure that you don't have any app code passing sql from the front-end, dropping the table may cause the app to break.

Download link http://www.toadsoft.com/toadmysql/FreewareDownload.htm

If you are using innoDB try this one SHOW TABLE STATUS FROM yourdatabasename LIKE 'T' http://dev.mysql.com/doc/refman/5.1/en/show-table-status.html

Answer 2

select table_name 
from information_schema.referential_constraints 
where referenced_table_name = 'parent table here';

Answer 3

select table_name
from KEY_COLUMN_USAGE
where table_schema = 'my_database'
and referenced_table_name = 'my_table_here';

This works.

Answer 4

Look at the KEY_COLUMN_USAGE table in the iformation_schema schema.

Answer 5

from the mysql command line: show table status