My first question in here. I like the site so much :)
I've a SQL table called Product. In that table I want to make a column for the ID of the product, and I really want to know the right way to write ID because I make a lot of ID columns in the long run.
So is it: "ID" or "Id" ?
And also a foreign key in another table, is that called ProductID or ProductId?
Thx guys.
Personally, I'd ProductID, ProductName etc in a Product table and for the FKs too to avoid having ID and Name columns everywhere
Just be consistent
There isn't a "right" way of doing it. Just be consistent. My personal preference is to use ProductId in both tables. If you use "ID" for all your tables and then join onto another table you will likely end up aliasing them anyway to distinguish between the two ID fields.
Capitalization in SQL is largely a matter of coding style. Consistency is the most important aspect. That said, "ProductId" looks a little like "Productld" (that's a lower-case-L before the "d") to me, so I'd prefer "ProductID" (or "productID" or "product_id").
As for prefixing column names with table names, it's too much in my book. Products.id is sufficient; Products.productID is redundant.
Well, "Id" is short for "Identification" so it "should" be "Id".
On the other hand, it's pronounced "I-D" rather than "id", so "ID" is acceptable too.
I'd prefer "ProductId" rather than just "Id" for a table's primary key, so that both sides of the foreign key relationship match.
As you prefer.
Most (many? some? the ones that I know?) frameworks seem to have adopted lower-case "id" for the primary key and "primarykeytablename_id" for the foreign key, at least for the default naming convention. I don't like this convention myself, since I like the key to have the same name on both sides of the relationship.
My preference is EntityNameID in both places (for example ProductID, OrderID, OrderDtlID, and so on).
I probably should never have taken that psychology class, but because there is a word "id", I always uppercase the abbreviation for identifier, thus I use "ID". I've experimented both with just using ID and ProductID for the primary key name. Because I use LINQ and simply map the class in the designer, I've taken to naming the columns the way I want them in my code. Because I'd prefer to have product.ID than product.ProductID, I use the shorter name. For foreign keys, I use the table/column format (with no separator), so the foreign key would become ProductID. This isn't an issue for me in my code, though, because I almost always use the mapped entity, e.g., cart.Product rather than the key itself, cart.ProductID.
EDIT: Note I'm assuming a target of the .NET framework, thus using (mostly), the naming conventions from .NET. If I were doing Rails development, these would probably be lowercase and I would use underscores as separators.
I tend to go for not having 'id' or 'ID'.
I always go for table - productName
pkProductName ProductName fkProductCode
and table - ProductCode pkProductCode productCode
so even when you are are using SQL or in code the relationships are explict and meaningful.