多变量依赖表的命名约定MySQL

Question

Conventions for normalized databases rule that the best practice for dealing with multivariable dependencies is spinning them off into their own table with two columns. One column is the primary key of the original table (for example, customer name, of which there is one), while the other is the value with has multiple values (for example, email or phone- the customer could have multiple of these). Together these two columns constitute the primary key for the spun off table.

However, when building normalized databases, I often find naming these spun off tables troublesome. It's hard to come up with a meaningful names for these tables. Is there a standard way of identifying these tables as multivariable dependency tables that are meaningless without the presence of the other table? Some examples I can think of (referencing the example above) are 'customer_phones' or 'customer_has_phones'. I don't think just 'phones' would be good, because that doesn't identify this table as related to and heavily dependent on the customers table.

Answer 1

In real life you end up running into a lot of combinations that vary a lot from each other.

Try to be as clear as possible in case someone else ends up inheriting your design. I personally like to keep short names in the parent tables so they don't end up being super long whenever the relationship grows or spans off new children.

For instance, if I have "Customer", "Subscriptions", "Product" tables I would end up naming their links like "Customer_Subscriptions" or "Subscriptions_Products" and such.

Most of the time it just gets down to what works better for you in terms of maintainability.

Answer 2

The convention we use is the name of the entity table, followed by the name of the attribute.

In your example, if the entity table is customer , the name of the table for the repeating (multi-valued) attribute would be customer_phone or customer_phone_number . (We almost always name tables in the singular, based on the idea that we are naming what ONE tuple (row) represents. (eg a row in that table represents one occurrence of a phone number for a customer.)