Re: The case preference of writing SQL, PL/SQL, SQL*PLUS comands/scripts

"Dino Hsu" <dino1_at_ms1.hinet.net> wrote in message news:0dfhht44o0un1gea4ri1bglifq6i59dbb0_at_4ax.com...
> Dear all,
>
> In Oracle PL/SQL training merterial, upper cases are used for key
> words, while lower cases for variable names (ex.1); but in many books
> about Oracle the reverse are used (ex.2).
>
> (ex.1)
> CREATE OR REPLACE FUNCTION sf_age
> (i_date IN DATE)
> RETURN NUMBER
> IS
> v_year1 NUMBER;
> v_year2 NUMBER;
> BEGIN
> v_year1 := TO_NUMBER(TO_CHAR(SYSDATE,'yyyy'));
> v_year2 := TO_NUMBER(TO_CHAR(i_date,'yyyy'));
> RETURN v_year1 - v_year2;
> END;
> /
>
> (ex.2)
> create or replace function SF_AGE
> (I_DATE in date)
> return number
> is
> V_YEAR1 number;
> V_YEAR2 number;
> begin
> V_YEAR1 := to_number(to_char(sysdate,'YYYY'));
> V_YEAR2 := to_number(to_char(I_DATE,'YYYY'));
> return V_YEAR1 - V_YEAR2;
> end;
> /
>
> Which one is the proper usage? Thanks for your comments.
>
> Dino
>

There is no such thing as "proper usage" as regards case sensitivity. The only proper usage is to decide yourself what should appear in uppercase/lowercase and stick to your decision. It's a matter of personal style and taste. The only exception is when you have to maintain code inherited by others: there you should stick with their taste to keep the coding style consistent (or modify it completely to your taste!).

If you use an editor capable of color-formatting then case-sensitivity does not really add to the readability, so you can even ignore it.

What makes statements more readable is spiltting the statement in many lines so that each clause appears in a new line and using proper identation.

---
Giorgos