Why is most SQL written in YELLING? [duplicate]

Question

On MySQL at least, the following two queries are functionally identical:

select * from users limit 0, 1000;
SELECT * FROM users LIMIT 0, 1000;

However, most example sites and most developers I've worked with use the latter, while I prefer the former.

Is there a reason to write SQL statements in all-caps? I find it to be more of a strain to hold the Shift key or to engage Caps-Lock for all SQL language statements.

Plus, I can't help but read statements as someone screaming:

DELETE FROM users WHERE id = 12345;
# OBLITERATE EVERYTHING FROM USERS WHERE THE ID IS 12345!!!!!!!!!!!!! NAO!

Answer 1

It's using case as a form of syntax highlighting. It makes the logic distinct from the table names and field names.

It's a form that predates new-fangled things like having more than one colour on a screen. We used to do it with UCSD pascal too.

Answer 2

Is there a reason to write SQL statements in all-caps?

1. Shows keywords more clearly, even if your IDE is fancy and highlights/colors.
2. Some editors/languages still might not have syntax highlighting.
3. People did it this way on because color highlighting didn't exist

Related to the last, an example to make things clear:

Take five chimpanzees. Put them in a big cage. Suspend some bananas from the roof of the cage. Provide the chimpanzees with a stepladder. BUT also add a proximity detector to the bananas, so that when a chimp goes near the banana, water hoses are triggered and the whole cage is thoroughly soaked.

Soon, the chimps learn that the bananas and the stepladder are best ignored.

Now, remove one chimp, and replace it with a fresh one. That chimp knows nothing of the hoses. He sees the banana, notices the stepladder, and because he is a smart primate, he envisions himself stepping on the stepladder to reach the bananas. He then deftly grabs the stepladder... and the four other chimps spring on him and beat him squarely. He soon learns to ignore the stepladder.

Then, remove another chimp and replace it with a fresh one. The scenario occurs again; when he grabs the stepladder, he gets mauled by the four other chimps -- yes, including the previous "fresh" chimp. He has integrated the notion of "thou shallt not touch the stepladder".

Iterate. After some operations, you have five chimps who are ready to punch any chimp who would dare touch the stepladder -- and none of them knows why.

Taken from this answer as it is directly applicable.

After a while, conventions become the way people do things even if/when they no longer make sense.

Answer 3

The SQL standard from 1992 required upper-case for keywords. Specifically, the list of reserved words is specified entirely in upper-case. See section 5.2 of the standard, ISO/IEC 9075:1992.

Now, almost all (possibly all) implementations didn't care. And, if I remember correctly, there have been subsequent editions of the SQL standard that did not require keywords be specified in upper-case.