Question

Just curious what is the best practice for solving the following issue. I have institutions, accounts and users tables. Institutions and accounts have a one-to-many relationship. Institutions and users have a one-to-many relationship. Users and accounts have a many-to-many relationship or alternatively they could have a many-to-all (or *) accounts. Meaning, that a user could be designated to all accounts, and any new accounts that are added to the institution the user would have access to without explicitly adding the relationship.

Answer 1

I’d do it like so:

Institutions
    InstitutionID INT IDENTITY(1,1) NOT NULL PRIMARY KEY
    Name VARCHAR(255)

Users
    UserID INT IDENTITY(1,1) NOT NULL PRIMARY KEY
    Username VARCHAR(255) NOT NULL
    InstitutionID INT NOT NULL

Accounts
    AccountID INT IDENTITY(1,1) NOT NULL PRIMARY KEY
    Account VARCHAR(255) NOT NULL
    InstitutionID INT NOT NULL

Users_Accounts
    Users_AccountsID INT IDENTITY(1,1) NOT NULL PRIMARY KEY
    UserID INT NOT NULL
    AccountID INT NULL

Have a UserID w/ a NULL entry in the Users_Accounts table have global (*) access. This way, you can determine the Institution on any Account and/or User, as well as their permissions.

Edit: Columns w/ the same name in different tables imply a Foreign Key. Please use them if you aren’t doing heavy loads.