how do I fetch a field?

mrdance

How do I fetch a field called \"KONTROLL\" and put it in a variable the easiest way?

Here\'s my line;

$result = mysql_query(\"SELECT KONTROLL FROM likvid WHERE ID=$idnummer[0]\");

I know that it will only fetch one line. I am a bit confused and new to mysql. What is actually stored in $result? And what do I write after this line?

Thanks!

brandonschnell

$result has the data but not in a format that is useable. next use "$row = mysql_fetch_array($result);" to get the row of day into an array starting at 0. as kontroll is the only field that was selected the variable will be $row[0] so we have:

$result = mysql_query("SELECT KONTROLL FROM likvid WHERE ID=$idnummer[0]");

$row = mysql_fetch_array($result);

echo "Kontroll: ",$row[0];

mrdance

I still have some problems. I get an MySQL error;

Supplied argument is not a valid MySQL result resource, pointing to this line;

$row = mysql_fetch_array($result);

All lines are (except connect);

$result = mysql_query("SELECT KONTROLL FROM likvid WHERE ID=$idnummer[0]",$db);
$row = mysql_fetch_array($result);

brandonschnell

something is failing before mysql_fetch_array().

1) verify your connect line is working and returning a link

2) if you do use mysql_query be sure you're selecting a database on a previous line.

mysql_select_db ("db_name");

or use mysql_db_query:

$result = mysql_db_query("db_name","SELECT KONTROLL FROM likvid WHERE ID=$idnummer[0]",$db);

3) be sure each function is returning a valid result and is actually working.

mrdance

thank you very much for the help!

lawnmowerman

Don't forget that using mysql_fetch_array() produces an associative array.

There are 2 ways of extracting data from it:

$kontroll = $row[0];
or
$kontroll = $row[KONTROLL];

Both return the same information.

If you are in the habit of always using the $row[0] method, you would probably be better of using mysql_fetch_row() since a numerically indexed array is created with 1 index per data item, strictly memory usage speaking.

mysql_fetch_array() creates an associative array with duplicated data, which COULD double the size of the array.

mysql_fetch_row( $result ) creates:
$row = array( "some data" );
"some data" is available as $row[0];

mysql_fetch_array( $result ) creates:
$row = array( 0 => "some data", "KONTROLL" => "some data" );
"some data" is available as $row[0] AND $row[KONTROLL].

-Rich

mrdance

thanks for the useful info! / Henrik