Testing for empty set in mysql

[slightlyeskew]

Hey guys,

I've been playing with mysql returns when I have either a NULL or an empty set return.

I've figured out how to check for a NULL return but I'd like to be able to test for the empty set.

I've tried this

<?php

//assume proper db connect

$test = $db->query("SELECT field1 FROM testTable WHERE field2 = 1000");
//field 1 and 2 both exist within testTable however there is no entry in field2 
//of 1000

//I've tried:
while($row = $testing->fetchRow(MDB2_FETCHMODE_ASSOC))
{
     foreach($row as $key => $value)
     {
         if(empty($value))
              {echo "worked";}
         else {echo "didn't work";}
      }
}
?>

When I run the page in localhost it loads without error but the page is blank.

I'll continue looking through the PHP manual but any suggestions would, as always, be greatly appreciated. Thanks so much!

[johanafm]

SELECT field1

This selects one column, namely field1

FROM testTable

The table to fetch field1 from

WHERE field2 = 1000

But only get field1 from the rows where field2 equals 1000. You claim that field2 has no value, so no rows would be fetched at all.

// Since field2 is supposed to be empty, nothing is retrieved from the db, so $row is false the first time.
while($row = $testing->fetchRow(MDB2_FETCHMODE_ASSOC)) {

// As explained above, each row is array('field1' => value_from_db)
foreach($row as $key => $value)
{
	// so, you only deal with 'field1', and that one is not supposed to be empty.
	if(empty($value))
	{
		echo "worked";
	}
	else
	{
		echo "didn't work";
	}
}
}

[slightlyeskew]

Awesome! Thanks so much johanafm it didn't even occur to me that the $row was evaluating to false.