Simple Database info retrieval

warzol

Hi. I am trying to simply pull some code from my database and I keep getting either empty responses or an error saying that "$TableName" does not exist if I try to use that instead of the actual "company_profile" name in the query. The name of the page is test.php & am linking to it with a text link that links to "test.php?id=1". The id being one is obviously my first record in the database. Anybody have any idea what I am doing. I am just learning PHP, so I can't see anything wrong with it. All the database information is correct:

<?php
$Host = "localhost";
$User = "getitdon_warzol";
$Password = "jemy45";
$DBName = "getitdon_testing";
$TableName = "company_profile";

$link = mysql_connect ($Host, $User, $Password);
$query = 'SELECT * FROM company_profile WHERE id="'.$_GET['id'].'"';
$result = mysql_db_query ($DBName, $query, $link) or die(mysql_error());

{	print ("Hello $result[name]</br>\n");
	print ("Your email is $result[email]</br>\n");  } 	

mysql_close ($link);
?>

Houdini

Try using this instead, it works for me.

<?php
$id=$_GET['id'];
$Host = "localhost";
$User = "getitdon_warzol";
$Password = "jemy45";
$DBName = "getitdon_testing";
$TableName = "getitdon_warzol";
$link = mysql_connect ($Host, $User, $Password)
	or die("Could not connect with the database. MySQL said: ".mysql_error());
$select = mysql_select_db("angel_test",$link)
	or die("Could not select the database. MySQL said: ".mysql_error());
$query = "SELECT * FROM $TableName WHERE id='$id'";
$result = mysql_query($query, $link) 
	or die(mysql_error());
$row = mysql_fetch_assoc($result);	
print "Hello ".$row[name]."</br>\n";
print "Your email is ".$row[email]."</br>\n"; 

mysql_close ($link);
?>

warzol

Cool, that seems to work much better. I am not sure what the difference is. I only have a very small understanding of PHP so far, but it looks like it should have the same output to it. Am I just using an old version of the code, or was something missing? I tried using the addition of the ".$row" line before using mysql_fetch_array, but kept getting errors, so took it out. Thanks for the help Houdini!

Houdini

mysql_fetch_assoc($result)is the same as mysql_fetch_array($result,MYSQL_ASSOC) minus al the extra stuff I just told it to fetch an assoociative array because unless written as I did in this post mysql_fetch_array() will return both an indexed array and an associative array which uses the feils names a a key of the associative array.

warzol

ah, cool. Thanks for the explanation. Now if I can just get it working in a full page, I will be in business 🙂 Thanks again!

leatherback

Hi Warzol,

Keep in mind that houdini's reply works, but when you try to retrieve more then one row from a database (Multiple records) you will need to loop through your data. In your first post, you have made a crucial little slip:
You define the query string just fine. You then run the query, that is good too.
But you have forgotten that the resultant of the query is not data, but an index to the database. You need to subsequently retrieve the records from the database, which is what houdini does here;

$row = mysql_fetch_assoc($result);

What I personally like to use:

$query = 'SELECT * FROM ".$compagny." WHERE id=".$_GET['id']."'; // be very carefull.. This is risky with regards to SQL injections
$result = mysql_query($query)
    or die(mysql_error()); // Unles you have multiple databases running, you do not need to provide the database handle

if(result)  // check that a result was obtained
  {
  while($row = mysql_fetch_array($result)  // As long as there are more records to be had
    {
    echo $row['compagny'];
    }
  }

Houdini

The reason I replied as I did was because he is passing the variable of id through the url (just one) and his own query was only going to give on row namely the row with the id passed with the URL so I saw no need to have a while loop at least in this particular code, although a while would still work with stiill the only result being one row of data returned. Actually I did have it coded that way out of habit but when I noticed what he was getting (basically just one row) I took the while out of the code I posted.

warzol

Very cool. I appreciate the info from both sides. This is simply practice right now, but now that I know the difference in the two formats I will experiment with both & I know which method to do under a specific circumstance. I am guessing, the removal of the "while" loop is simply to save a little time in the processing in code, correct? Thanks again guys/gals.