currency - selecting and echoing

[ATS16805]

i have values in a table which represent currency, US$. i need to do no calculations on these values. they could be numbers of chickens, and it would still function the same.

if i wish to print this value to screen, should i just use the $ in my html block, or should i use MySQL or PHP to show the dollar sign to represent that it's currency?

from your experience, what do you think is best? i want to get into a "good habit" here, so maybe i should use something that would work if i were doing calcs on the numbers, or what not.

thanks!

edit:
i tried using \$ in the html block, which seems to work fine for now, but i am interested in your commentary if you wish to add anything here.

[bpat1434]

In PHP, if you use the single quotes to define text strings, then the PHP interpreter will NOT evaluate "$" variables. I think this is something for you to consider. Take this example:

<?php
$the_var = 'Some Unknown Value or String';

echo "$the_var <br>";
echo '$the_var <br>';
?>

That will output:

Some Unknown Value or String
$the_var

So you can use this to your advantage when dealing with monetary units and items. You can use the single quote string to start the display. Something like:

<?php

echo '$'.$the_var.'<br>';

My normal practice is to use all single-quote strings. This way, I know that it will be interpreted literally and not as a variable. When I need to include the variable value, I just concatenate the string so I know for a fact that the value of the variable is given, not the variable name itself.

Hope that helps you decide.

~Brett

[ATS16805]

it does help! it's certainly a new, interesting perspective on use of variables-- something i wasn't aware of before this, but which i surely learned along the way during the fundamentals, but i don't recall it!

what i was asking, and maybe you've answered and i simple don't see it yet, is do i need to, or can i / should i tell PHP something about this variable being currency instead of it being just "a number"? if so, how is currency best handled for PHP and storage/ calc (if needed) from MysQL? is it all just "a number is a number is a number" and i simply add the '$' character later so that it makes sense to the viewer?

[bpat1434]

Well, I didn't really answer your question, but now I will try.

If you look at mySQL column types, they are:

• VARCHAR

• TINYINT

• TEXT

• DATE

• SMALLINT

• MEDIUMINT

• INT

• BIGINT

• FLOAT

• DOUBLE

• DECIMAL

• DATETIME

• TIMESTAMP

• TIME

• YEAR

• CHAR

• TINYBLOB

• TINYTEXT

• BLOB

• MEDIUMBLOB

• MEDIUMTEXT

• LONGBLOB

• LONGTEXT

• ENUM

• SET

• BOOL

• BINARY

• VARBINARY

So you can see that mySQL doesn't have any "Currency" type. So you would store your currency as a number (INT). From there, you just need to decide what your basic overall default currency is (dollar, pound, looney, frank, Euro). Then you can do conversions for each individual currency.

PHP doesn't care about currency from my experience. PHP doesn't really interpret currency, rather it just interprets code. So $1 vs 1 Euro in PHP is just numbers. You the coder have to decide how you want to display or modify the number. Here's what I would do:

Figure out all the major conversions from your default currency:

• Dollar => Pound

• Dollar => Euro

• Dollar => Frank

• etc., etc., etc...

Then write a small function that converts from your default currency (Dollar) to the user currency (Pound, Frank, Euro, etc....). Then when you store your price in the database, just store it as an integer, and base it on the default value (Dollar). That way, the prices are "real-time" and your code is just a matter of defining what the users currency symbol is and converting the number from US Dollars.

~Brett

[ATS16805]

Brett, thank you. I'm sure this will come in handy.

for the record, my question arises from previous experience w/ the flat-file-on-steriods which is MS Access, and also my lame-attempt at learning Server Side Scripting by way of DreamWeaver and ColdFusion-- not that ColdFusion is by any means a poor language, but my approach was poor, being too reliant upon and concerned w/ a Software's own (DW) configuration and it's interaction w/ its nearly proprietary db server (CF), and not reliant enough upon the interactivity of the code and the db server and the db itself, so i hope you can understand my confusion, and why i was inclined to ask the question about currency. in MS Access, in case you or someone else reading this is unaware, you can declare a data-type as currency. and in my previous experimentationn w/ CF and DW, i was using MS Access ODBC connection.

blah, blah. but, thanks for entertaining my wandering, lost ways. things make more sense the more and more i focus on learning the fundamentals of PHP and MySQL and try less to relate it to my own logic. if that makes any sense. 🙂