How to extract many-to-many to many-to-many in one query
How to find and remove duplicates.
How to drop multiple tables named with prefix (or named with similar pattern).
How to delete related records with one query (using ON DELETE CASCADE foreign key).
How to delete records from multiple tables with one query.
How to select latest one from each category (group-wise max in a group query)
How to rank records (grouped ranking).
Custom ordering (order rows by my order).
Example shows how to rank records in a table.
Select N latest records in a group.