Random decimal number

[silversand]

I'm hoping someone can show me how to get a random decimal number. I've googled and can't find anything that works.

 

I need to find a random number between 1.0 and 10.0

 

I can get a random whole number no problem, but decimals aren't working.

 

When I finally get that working, ideally I'd like to be able to find a random number between two decimals (like above) but also have a small chance of getting a decimal slightly higher than the two given. So, for example, maybe a random decimal between 3.5 and 6.0, but a slight chance of getting 6.2?

 

Thank you very much for any help!

[mikecampbell]

It depends how many decimal places you want, but you could use

mt_rand(0, 100)/10;

to get numbers between 0 and 10 with one decimal place.

[silversand]

I've tried that and I get a whole number or a 0. This is the solution I found while googling but for some reason it never works for me.

[mikecampbell]

It works for me. Are you echoing the random number immediately after you generate it?

[kenrbnsn]

Please post your code between

tags.

 

Ken

[silversand]

No, the number is generated and inserted into the database first and then displayed on the page when called. Even when I check the database the number is still whole or 0.

[kenrbnsn]

How is the database field defined?

 

Ken

[silversand]

$headgenes = mt_rand(0, 100)/10;


mysql_query("INSERT INTO ".$prefix."owned VALUES ('',  '$d[$i]', '$name[$i]','$loggedinname','0','0','0','0','0','0','0', '$code',  '','$alts','ftrade','no','$gend','$headgenes')");

[cyberRobot]

Is the field type set to something that can hold decimals? If you're using MySQL, you might want to review:

http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html

[silversand]

Aaaaah, I think they may be it. The mysql field is set to int. I'm off to go fix that now and will report back. Thanks!

[silversand]

Hmm, I changed the mysql to decimal but I still end up with a whole number being inserted...

[cyberRobot]

Does it display the decimal part if you print $headgenes before the SQL query? For example:

 

<?php
...

$headgenes = mt_rand(0, 100)/10;
echo $headgenes;


mysql_query("INSERT INTO ".$prefix."owned VALUES...
?>

[silversand]

Yes. It just doesn't seem to want to store as a decimal in the database

[cyberRobot]

What happens if you display the query; is the decimal still there? Note that you may need to modify the code a little:

 

<?php
...

$sql = "INSERT INTO ".$prefix."owned VALUES ('',  '$d[$i]', '$name[$i]','$loggedinname','0','0','0','0','0','0','0', '$code',  '','$alts','ftrade','no','$gend','$headgenes')";

echo $sql;

mysql_query($sql);

...
?>

[silversand]

No, no decimal.

[cyberRobot]

So what does the code between "$headgenes = mt_rand(0, 100)/10;" and the SQL query look like?

[silversand]

Wait! Just did it again and there IS a decimal there when I echo it.

 

This is what came up.

 

INSERT INTO owned VALUES ('', '', '','','0','0','0','0','0','0','0', '2131', '','','ftrade','no','','6.5' )

 

Still doesn't work when I try to use it in the code and display it from the database.

[cyberRobot]

It sounds like you changed the database field to "decimal"; what did you enter for the "Length/Values" part of the field?

 

Note that it needs to be set to something like "6,2" where the number after the comma represents how many decimal places you want to go.

[silversand]

Woohooo! That was it! I didn't have the length/values set correctly. Thank you! Thank you!

 

 

Can I press my luck for my other question? How to get a random decimal between two numbers with a chance of a slightly higher result?  So the result from a number between 2.2 and 7.1 would be something like 5.4, but could possibly be 7.2?