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how to use row_pointer

Posted: Tue Apr 22, 2003 4:12 am
by MuffinMan
this is my first post here - so hello people!

now to my question: i did a dynamic linklist where everybody can enter url's and they are shown again in the list, so this part works quite well already. i gave the values in the database an ID (it's an own column) and i use this to query specific lines. now when i wanna update one value thats no problem but when i wanna delete the whole row i have one missing ID-number which hinders my query from working right, so i would have to replace the ID after every delete - now my question is is there any way to read the line-number without giving it an explicit ID, i read about that row_pointer but i don't really know how to use it yet, is it incremented by every operation quite like a streamreader or do i have to set it? and is it possible to do a query like WHERE row_pointer = something... ?

thanks in advance!

oh and another thing: what data-type should i take to store a complete file (about 1 -2 mb) in a database - i know this might sound strange but it would really help me...

Posted: Tue Apr 22, 2003 6:41 am
by McGruff
It's hard to say what would help without knowing more about the code.

mysql_data_seek() might be what you're looking for - but what is the exact problem with deleting a row and losing an ID?

Posted: Tue Apr 22, 2003 7:54 am
by MuffinMan
i think i found what i am looking for:

$result = @mysql_fetch_array($resultset)

my problem was that i could query like SELECT all data WHERE bla = 0 but then i couldn't read the single lines within the result, only the first one, so i did that query for every single ID again and again... will have to try that if it works, anyway thanks for the reply!

btw: i'm gonna remake the whole thing anyway (probably not for the last time), somehow i never manage to have a program done - there's always something to change - i mean this one is already running but it's performance should be horrible and it's ugly code ;o) guess you know what i mean...

Posted: Tue Apr 22, 2003 8:16 am
by McGruff
Is this what you're looking for:

Code: Select all

<?php

$mysql = "SELECT * FROM table_name";
$query = mysql_query($mysql) or die("Cannot query the database.<br>" . mysql_error());

while ($result = mysql_fetch_array($query)) {
    echo $result['column1'];
    echo $result['column2'];
    echo $result['column2'];
    // .. etc
}

?>

Posted: Tue Apr 22, 2003 10:52 am
by MuffinMan
well that's not exactly what i wanted to do but i will adjust my program anyway so this will have to work:

Code: Select all

<?
$connection = @mysql_connect($dbhost,$dbuser,$dbpasswd);

mysql_select_db($dbname) or die( "Unable to select database");

if (!$connection) 
{
	echo "no connection to the database possible!\n";
	exit;
}

$query = "SELECT * FROM $table WHERE sectionID='1'";
$query_result_handle = mysql_query ($query) or die("Query failed"); 

$num_of_rows = mysql_num_rows ($query_result_handle) or die ("The query: '$query' did not return any data"); 
print "The query: '$query' returned $num_of_rows rows of data."; 

$row = mysql_fetch_row ($query_result_handle);

print "<b>Fetching row #$count from the query.</b>"; 
print "Value stored at the first index position of \$row: '$row[0]'"; 

$row = mysql_fetch_row ($query_result_handle);
print "<b>Fetching row #$count from the query.</b>"; 
print "Value stored at the first index position of \$row: '$row[0]'"; 

mysql_close();
?>
i didn't know that every mysql_fetch_row gives the next row, so i did every time a new query for the next line-ID-number i have in my table...
this way i still can't say give me the stuff at row-number 3 or something (without having a lineID-column to query) but you can't have everything...

thanks for helping!