Why should I capitalize my SQL keywords? [duplicate]

Question

I agree with you - to me, uppercase is just SHOUTING.

I let my IDE handle making keywords stand out, via syntax highlighting.

I don't know of a historical reason for it, but by now it's just a subjective preference.

Edit to further make clear my reasoning:

Would you uppercase your keywords in any other modern language? Made up example:

USING (EditForm form = NEW EditForm()) {
    IF (form.ShowDialog() == DialogResult.OK) {
       IF ( form.EditedThing == null ) {
          THROW NEW Exception("No thing!");
       }
       RETURN form.EditedThing;
    } ELSE {
       RETURN null;
    }
}              

Ugh!

Anyway, it's pretty clear from the votes which style is more popular, but I think we all agree that it's just a personal preference.

I think the latter is more readable. You can easily separate the keywords from table and column names, etc.

One thing I'll add to this which I haven't seen anyone bring up yet:

If you're using ad hoc SQL from within a programming language you'll have a lot of SQL inside strings. For example:

insertStatement = "INSERT INTO Customers (FirstName, LastName) VALUES ('Jane','Smith')"

In this case syntax coloring probably won't work so the uppercasing could be helping readability.

From Joe Celko's "SQL Programming Style" (ISBN 978-0120887972):

Rule:

Uppercase the Reserved Words.

Rationale:

Uppercase words are seen as a unit, rather than being read as a series of syllables or letters. The eye is drawn to them, and they act to announce a statement or clause. That is why headlines and warning signs work.

Typographers use the term bouma for the shape of a word. The term appears in paul Saenger's book (1975). Imagine each letter on a rectangular card that just fits it, so that you see the ascenders, descenders, and baseline letters as various "Lego blocks" that are snapped together to make a word.

The bouma of an uppercase word is always a simple, dense rectangle, and it is easy to pick out of a field of lowercase words.

What I find compelling is that this is the only book about SQL heuristics, written by a well-known author of SQL works. So is this the absolute truth? Who knows. It sounds reasonable enough and I can at least point out the rule to a team member and tell them to follow it (and if they want to blame anyone I give them Celko's email address :)