When a record or row in a MYSQL table is no longer necessary to keep around, you can get rid of it using the DELETE statement.
The syntax is: DELETE FROM tablename WHERE column = data;
DELETE FROM pets WHERE name LIKE "Tamika";
DELETE FROM pets WHERE id = 3;
In short, the table and the record must both in some way be identified in order to delete the proper data.
As with all delete statements, take care not to delete too much or the wrong data!