Re: Using q() to define a query

On 2008-01-14 13:07:17 +0100, Jenda Krynicky wrote:
From: "Peter J. Holzer" <hjp@xxxxxxxxx>
As an aside, the SPL programming language[2] allows the terminator of a
here document to be indented and to strip off everything up to and
including some character from each line, so that could be written like
this:

function foo() {
some;
code;
here;
if (bla) {
more;
code;
here;
var sql = >>SQL|
|SELECT
| jo.departure_date AS departure
|, eq.name AS equipment
|, dp.full_city AS departure_city
|, ap.full_city AS arrival_city
|, ca.name AS carrier_name
|, jo.number
|[...]
SQL;
even;
more;
}
code;
here;
}

That kinda defeats the purpose of heredocs, namely allowing me to
copy&paste some data into/out of the script without having to escape
or modify anything.

In most cases this works with q{} just the same (the only exception is
the sequence \\, which unfortunately represents only a single backslash
inside q{}.

If you do this and then need to test and tweak the SQL in some UI
provided by your database you have to go and strip and later
reintroduce the |s.

Yes, that works for SQL, as I wrote, but not for multi-line strings in
general, where leading whitespace may matter (think of formatted text
output).

Before Clifford introduced that feature into SPL, we discussed several
formats. I think one of them included a "column 0 marker" in the first
line - something like that:

var sql = >>^SQL|
SELECT
jo.departure_date AS departure
, eq.name AS equipment
, dp.full_city AS departure_city
, ap.full_city AS arrival_city
, ca.name AS carrier_name
, jo.number
[...]
SQL;

where everything to the left of the marker ("^" here) would be stripped
off. That would simplify cut'n'paste a bit. I don't remember why he
didn't do it that way, but one obvious problem with this approach is
that "to the left of" is ambiguous if tabs and spaces are mixed.

Not for me, I'd rather have a few lines that are not indented.

As I wrote I prefer just using q{}. As you can see in my example, it has
all lines indented and you can simply cut and paste.

hp

--
_ | Peter J. Holzer | If I wanted to be "academically correct",
|_|_) | Sysadmin WSR | I'd be programming in Java.
| | | hjp@xxxxxxxxx | I don't, and I'm not.
__/ | http://www.hjp.at/ | -- Jesse Erlbaum on dbi-users

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