PHP: syntax for using boolean variables in MYSQL database for logic

Question

php/mysql noob with question. MYSQL does not seem to have a preferred way to store boolean values. I decided to go with Tiny(int) at the suggestion of someone on a message board who said this is equivalent to True/False. I would think that True =1 and False =0...maybe that's assuming to much... Anyway put 1 values in mysql dbase for testing. They showed up in phpAdmin as "1" for what that's worth.

I'd like to retrieve these values and if TRUE show picture and if false, not show it. So after connecting with dbase and running successful query that returns other text values fine, I wrote...

if ($row['email'] == TRUE)
{
echo "<img src='images/email.png'>";
}

Alternatively in place of TRUE, I've tried 1, '1' "1" 'TRUE' etc.

If I just echo $row('email'), I get 1. However, the above logic does not work. The condition is never meant and the image never shows. I tried turning it around with != but still can't get it to work. From what I've read, booleans in MYSQL can be a bit flaky but this seems pretty basic.

Note. With above code, there is no error. It just never evaluates the statement in parentheses as true to execute conditional. Could it be a syntax error??? or what am I missing.

Thanks for any suggestions!

What does var_dump($row['email']) result in?

webbiedave
– webbiedave

2012-03-13 21:40:12 +00:00
Commented Mar 13, 2012 at 21:40 — webbiedave
– webbiedave, Commented Mar 13, 2012 at 21:40
put an echo before the if.

Karoly Horvath
– Karoly Horvath

2012-03-13 21:40:55 +00:00
Commented Mar 13, 2012 at 21:40 — Karoly Horvath
– Karoly Horvath, Commented Mar 13, 2012 at 21:40

iinsaneii · Accepted Answer · 2012-03-13 21:44:45Z

2

If i understand correctly your using

if($row['email'] == 1){ 
echo "<img src='your-path.jpg'></img>";
}else{
 // do nothing if false
}

answered Mar 13, 2012 at 21:44

iinsaneii

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Comments

webbiedave · Accepted Answer · 2012-03-13 21:44:46Z

2

I decided to go with Tiny(int)

That's exactly how it's done by millions around the world.

I would think that True =1 and False =0

That is how you should interpret it.

if ($row['email'] == TRUE)
does not work

This should absolutely work and can be tested simply with:

$row['email'] = '1';
echo $row['email'] == true; // output: 1

Double check the contents of $row, i.e., var_dump($row) to ensure that the data is being properly gathered from the database. Check for any errors returned from the database. Also check for errors returned by PHP by placing this at the top of your script:

ini_set('display_errors', 1);
error_reporting(E_ALL);

answered Mar 13, 2012 at 21:44

webbiedave

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1 Comment

user1260310 Over a year ago

Thanks everyone It turns out it was a dumb mistake on my part, trying to evaluate the statement after I'd already closed the fetching of data with a misplaced }. Fixed it by moving the brace. TRUE without quotes works.

pp19dd · Accepted Answer · 2012-03-13 22:04:36Z

1

I use enums, because they're more readable in certain situations; especially when dealing with an old table.

Ie, "isDeleted" can have values of 1/0 or as an enum, "Yes/No" or even better: "Live/Deleted."

All three describe the same state, but the last example punches you in the face more heavily.

Only complication is inputting it, but, booleans are the bane of all that is HTML anyway. MySql queries for saving are fairly sensible:

mysql_query( sprintf(
    "update table set isDeleted='%s' where id=3",
    ($myvalue === true ? 'Live' : 'Deleted')
));

answered Mar 13, 2012 at 22:04

pp19dd

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