[RESOLVED] how to print msg when query finds nothing

[harkly]

quick question (I hope)

when doing a query and there are no results returned I want to print out a message saying so but I am not sure how to do that with my current code.

this is just a snipette of my code and I am getting no errors

if(empty($religion)) {
  $result = mysql_query("SELECT user.userID, user.gender, user.genderPref, user.city, user.state, photos.photo_1,
                                CURDATE(), (YEAR(CURDATE())-YEAR(birth_date)) - (RIGHT(CURDATE(),5)<RIGHT(birth_date,5)) AS age
                        FROM user
			LEFT JOIN photos
			ON user.userID = photos.userID
			LEFT JOIN about_me
			ON user.userID = about_me.userID
			LEFT JOIN bkgd
			ON user.userID = bkgd.userID
			WHERE zip IN (". $zips_in_range .") AND user.bd_year <= $year1 AND user.bd_year >= $year2 AND genderPref = $gender AND gender = $genderPref AND about_me.smoking = $smoke
			ORDER by user.userID")or die('query 3 failed'); }
else {
  $result = mysql_query("SELECT user.userID, user.gender, user.genderPref, user.city, user.state, photos.photo_1,
       CURDATE(), (YEAR(CURDATE())-YEAR(birth_date)) - (RIGHT(CURDATE(),5)<RIGHT(birth_date,5)) AS age
			FROM user
			LEFT JOIN photos
			ON user.userID = photos.userID
			LEFT JOIN about_me
			ON user.userID = about_me.userID
			LEFT JOIN bkgd
			ON user.userID = bkgd.userID
			WHERE zip IN (". $zips_in_range .") AND user.bd_year <= $year1 AND user.bd_year >= $year2 AND user.gender = $genderPref AND user.genderPref = $gender AND about_me.smoking = $smoke AND bkgd.relg = $religion
			ORDER by user.userID")or die('query 4 failed'); }}
}
if (empty($result)){
  echo "Sorry No Results found, please try again with a boarder search area."; }
else { ...

I have also tried this but always get the "No results" message

if ($result = "null"){
  echo "Sorry No Results found, please try again with a boarder search 
else { ...

also tried this but get no message

if (!$result){
  echo "Sorry No Results found, please try again with a boarder search 
else { ...

[dagon]

mysql_num_rows

[harkly]

Perfect!! Thanks so much!

[bradgrafelman]

Just to elaborate a bit...

The manual page for [man]mysql_query/man explains type of values it can return:

PHP Manual wrote:

For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error.

Notice that nowhere does it say the function will return a null value just because there are no rows found. A SELECT query that doesn't match any rows isn't an error, it's just a query that returns a rather boring result set.

Furthermore, the manual even tells you how to do what you're asking (and what dagon suggested above):

PHP Manual wrote:

Use [man]mysql_num_rows/man to find out how many rows were returned for a SELECT statement

Finally, a note about the things you tried:

harkly wrote:

if ($result = "null"){ 
  echo "Sorry No Results found, please try again with a boarder search 
else { ...

Two things wrong with your syntax here. First, you're trying to assign the value of $result, not compare it. To do the latter, you'd need to use a comparison operator, e.g. the double equal sign (==).

Second, the string "null" is very different from a null value. The former is a string consisting of four letters, while the latter is the absence of any value, e.g.:

echo "Length: " . strlen("null"); // Length: 4
echo "Length: " . strlen(null); // Length: 0

harkly wrote:

if (!$result){ 

The manual's explanation of what [man]mysql_query/man returns should tell you why this isn't the comparison you're wanting.

[dagon]

bradgrafelman, you have to much free time, get a job :-)

[bradgrafelman]

dagon;10957658 wrote:

bradgrafelman, you have to much free time, get a job :-)

Already got one (I'm there right now, actually - on break though) as a software engineer (using Java, not PHP unfortunately).

[harkly]

Thanks for the more detailed info, bradgrafelman.