pull down to refresh

which came first, SQL or relational databases?
If Treasury uses COBOL, then their systems think the year is 1925
Yes, System R (another IBM product) was widely considered to be first commercial relational db. This was late 60s I think.....sometime in the 70s that "migrated" into what we know as SQL.
Interestingly, really "SQL" is just the query language....so what we call "SQL DB" is a relational database with a "SQL Syntax" interface.
reply
I guess SSN is not a primary key
reply
109 sats \ 2 replies \ @freetx 12 Feb
Even if its not a primary key, it could still have UNIQUE constraint applied.
I imagine there a valid reasons why they don't have it set. The amount of people either unintentionally or intentionally using the wrong SSN is probably non-trivial. Having it as a unique/primary key would prohibit you from doing some other transaction involving that person.....
I mean technically a SSN is "only" supposed to refer to your social security account, it was never intended to become a universal identifier....
reply
I can't wait for the next judical activist to rule on primary keys, foreign keys, unique constraints, inner/outer joins.
No master/slave architecture! 13th amendment prohibits any kind of slave.
reply
Is there a good reason for using the wrong SSN?
reply