Choose a side to combine the relationship into both sides need a foreign key to the other entity in the relationship with the UNIQUE quantifier on both.
Combine the relationship into the many side with a foreign key to the one side with an ON DELETE and ON UPDATE quantifier.
Create a new table for the relationship with foreign keys for every participating entity set as well as a composite primary key from the participating entity keys.
Weak entities are their own table and have a foreign key to their "owner" entity set. Their primary key is a composite primary key between the weak entity set's candidate key and the owners primary key. Their relationship to the "owner" is combined into the weak entities table.
Aggregation is represented by creating a table for the aggregation which is treated as an entity set, it's primary key's are the minimum primary keys of the constituting entities.