relational-database

In class, we are all 'studying' databases, and everyone is using Access. Bored with this, I am trying to do what the rest of the class is doing, but with raw SQL commands with MySQL instead of using Access. I have managed to create databases and tables, but now how do I make a relationship between two tables? If I have my two tables like this: CREATE TABLE accounts( account_id INT NOT NULL AUTO_INCREMENT, customer_id INT( 4 ) NOT NULL , account_type ENUM( 'savings', 'credit' ) NOT NULL, balance FLOAT( 9 ) NOT NULL, PRIMARY KEY ( account_id ) ) and CREATE TABLE customers( customer_id INT NOT

I have a 4 types of users and each have specific data, but they also share commun data, like username , password .. My first thought is to create a main users table with user_type column. Then when querying user data i can just first select their user_type and then depending on the output run a different query to grab "user type" specific data. I am not fond of this as i wish i could grab all user related data with one query and ideally using Foreign Keys. Second idea is to not have a user_type column in the users table and instead use foreign key that from a specific user type table will

I've found the concept and meaning behind these methods to be a little confusing, is it possible for somebody to explain to me what the difference between has and with is, in the context of an example (if possible)? lukasgeiter With with() is for eager loading . That basically means, along the main model, Laravel will preload the relationship(s) you specify. This is especially helpful if you have a collection of models and you want to load a relation for all of them. Because with eager loading you run only one additional DB query instead of one for every model in the collection. Example: User