array problem ....

corporateboy

Okay I have 4 variables

$p1
$p2
$p3
$p4

They are populated out of a sql query and will either hold the value of a file name or be null.

How do I put the none null ones into an array so I can then select 2 (if there are 2 or more file names in the array or 1 if there is 1, or none if they are all null) randomly from that array (cannot select the same one twice) for display on a page.

help me ! it would be greatly appreciated, im a bit of a newbie.

mogster

Ehm...
You could filter a bit in your query?

$daQuery = ("SELECT distinct filename, size, filetype FROM table WHERE filename <> '0'");
while($fnamerow = mysql_fetch_array($daQuery)) {
echo "Filename: ".$fnamerow[filename]." Filetype: ".$fnamerow[filetype]." Size: ".$fnamerow[size];
}

Just a suggestion 😉

knutm

corporateboy

sorry I don't think I was clear enough

the four variables are populated from one mysql record (there are 4 photos for each article in the system) - I want to get two of the photos randomly and display.

So I don't know how to filter in the query because it is a simple select where id = '$id' and returns something similar to

photo1 | photo2 | photo3 | photo4 |

1.jpg | 2.jpg | 3.jpg | NULL |

blr32

From: http://www.mysql.com/doc/en/Mathematical_functions.html

RAND (N)
Returns a random floating-point value in the range 0 to 1.0. If an integer argument N is specified, it is used as the seed value.
...
In MySQL Version 3.23, you can, however, do: SELECT * FROM table_name ORDER BY RAND()
...

Note that a RAND() in a WHERE clause will be re-evaluated every time the WHERE is executed. RAND() is not meant to be a perfect random generator, but instead a fast way to generate ad hoc random numbers that will be portable between platforms for the same MySQL version.

I hope this could give you a clue.

corporateboy

that still returns the NULL values though, and I want to select two randomly of the none null values - ie using rand() will still give me the chance of selecting a null value where there exists a real one

I'm working on a php solution involving testing the variables and adding them to an array if they exist, then choosing two randomly from the array and if they match each other choosing a different two until they don't match - just need to work the code for that.