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Development Tools Database Foundations Joining Relational Data Between Tables in SQL Keys and Auto-Incrementing Values

Posted by Jim Withington
Jim Withington
12,025 Points

Quiz Question #1 clarification (parentheses in MySQL)

I had a bunch of trouble with this question, because I keep leaving out the parentheses needed in the answer:

Create a genres table called "t_genres" with an auto incrementing primary key called "pk_id" and a unique column called "uk_name" that can't be null. The "uk_name" is a varchar of up to 45 characters.

It seems like MySQL doesn't call for parentheses very often...until it does. :grinning: Are they only needed because we created two columns, separated by a comma? Is there an easy way to understand when those parentheses are needed?

Thanks!

1 Answer

Konstantin Lopatin
Konstantin Lopatin
29,193 Points
Konstantin Lopatin
Konstantin Lopatin
29,193 Points

As far as I had experienced, parentheses are needed when you deal with several elements. E.g. you can have a condition like variable = 2 or variable in (1,2,3)

Or parentheses may be a part of a function like IFNULL(X,Y), of cource