PHP PDO object null check

[ashutoash]

I am using PDO to run query's and get data. How do I check if the PDO query returned a null value. I tried empty but that doesn't work because PDO array will always contain an SQL query. I want to check if the return value of that query is NULL :confused: . Help please.

[cunoodle2]

Can you see if it is NULL???

 

Try a var_dump() on the values as likely it is an array

[ashutoash]

I want to see if the return value is NULL. Based on that I want to display a NO DATA label on my front end. But I am unable to do it. Hence this question.

[cunoodle2]

Can you show your code?

[ashutoash]

@cunoodle2: Here is what I am doing. Its a simple query:

 

$result_download = $db->query("SELECT download_hits as total_hits from date1_dcerpc where time = 1314712800 ");

 

I know there are no download_hits at 1314712800 as there is no entry for 1314712800 in the table so the return should be null. I want to know how to check if the PDO object returns null.

[Jet4Fire]

check errorCode()

 

example:

if ($db->errorCode() == '00000') {
    // do something
} else {
    // display error
}

[cunoodle2]

Technically your query will NOT return NULL.  It will return zero results.

 

From the Manual: Counting rows returned by a SELECT statement

 

For most databases, PDOStatement::rowCount() does not return the number of rows affected by a SELECT statement. Instead, use PDO::query() to issue a SELECT COUNT(*) statement with the same predicates as your intended SELECT statement, then use PDOStatement::fetchColumn() to retrieve the number of rows that will be returned. Your application can then perform the correct action.

 

 

<?php
$sql = "SELECT download_hits as total_hits from date1_dcerpc where time = 1314712800";
if ($res = $conn->query($sql)) {

    /* Check the number of rows that match the SELECT statement */
  if ($res->fetchColumn() > 0) {

        /* Issue the real SELECT statement and work with the results */
         $sql = "SELECT download_hits as total_hits from date1_dcerpc where time = 1314712800";
       foreach ($conn->query($sql) as $row) {
           print "Name: " .  $row['download_hits'] . "\n";
         }
    }
    /* No rows matched -- do something else */
  else {
      print "No rows matched the query.";
    }
}

$res = null;
$conn = null;
?>

 

[cunoodle2]

I may have botched that a little on the post.  Here is the link to the page that I got that info from..

 

http://php.net/manual/en/pdostatement.rowcount.php

[ashutoash]

Thanks cunoodle2 and Jet4Fire. The errorcode thing did not work but I am doing a count of rows and if count == 0, I am displaying ND.  .

This is solved. But most of my PDO statments, if there is no data, give out a warning PHP Warning:  Invalid argument supplied for foreach(). I read somewhere that @ can be used to suppress these but that doesn't work. How can I suppress these? Those warnings are filling up my logs like anything.