title: Constraint detail from information_schema (on update cascade, on delete restrict)
body: <p>Almost all the information I had needed about a database, I  could find in information_schema</p>
  
  <p>This time I needed to read details of <strong>all foreign keys in a database through single query</strong> I found every thing in information_schema.key_Column_usage but could not find the <code>constraints like on delete, on update</code></p>
  
  <p>I could do <code>show create table</code> for all individual tables. But is there any way to get these details through some select query like this?</p>
  
  <pre><code>SELECT CONSTRAINT_NAME, TABLE_NAME,COLUMN_NAME, REFERENCED_TABLE_NAME, 
  REFERENCED_COLUMN_NAME FROM information_schema.`KEY_COLUMN_USAGE` WHERE 
  table_schema = 'mydbname' AND referenced_column_name IS NOT NULL
  </code></pre>
  
  <p>It is doing the job well but just missing constraints like <code>on delete, on update</code> How can I get those values as well so that I can get all info about foreign keys in a single query?</p>