Creating a php array

jamesloi

Hi,

I am assigning an array from a mysql table by using..

$row = mysql_fetch_array($result)

When i echo ("$row[0]"); it returns the correct result..But when i eco ("$row[1]"); it is empty. Do i need to make $row an array or something..? any help would be appreciated.

khaldryck

it just mean that the result in $row[1] is empty ...
check that the 2nd value returned by your query is not empty.

better to use $row["fieldname"] that way you always know what field you're using.

or maybe you're thinking $row[1] to contain the 2nd row of your query ..
that's not the case.

ex: select id, name from table
$row[0] will contain the id, $row[1] will contain the name for that row.

you have to loop if you want to get next id and name.
while($row=mysql_fetch_array($result)) {
echo $row[0].",".$row[1]."<br>";
}
this will display each row returned by your query.

RedDragon

hi,

your value $row is already an array...

if you echo $row['1'] and get nothing this means that the table you queried / the selection in the query was only one field of the table...

post the query and the structure for further explanations...

jamesloi

Basically i am trying to update a value in a table by referencing the Item_code

	$query2 = "SELECT qty FROM cart";

$result = mysql_query($query2);

while ($row = mysql_fetch_array($result)){

           for ( $i = 0 ; $i < 10 ; $i++ ) {

            $query4 = "UPDATE CD_data SET  stock_level=stock_level-$row[i] WHERE Item_code=cart.itemId";
           mysql_query($query4);
             echo ("$row[1]");
		}
}

khaldryck

there are no value in $row[1] as your query only return 1 field.

the to access that value, you have to use $row[0]

now i don't understand the use of your for($i ...) loop.

why do 10 times the same update ?
if you need to update your db removing 10 times $row[0] from your stock
you can compute the result like this :

$query2 = "SELECT qty FROM cart where qty>0";  

$result = mysql_query($query2); 

while ($row = mysql_fetch_array($result)){ 

$to_remove=$row[0] * 10;
$query4 = "UPDATE CD_data SET stock_level=stock_level-".$to_remove." WHERE Item_code=cart.itemId"; 
mysql_query($query4); 
echo (whatever you want here);
}

jamesloi

Hi,

The query i am using is returning 2 values (qty 2, 2). i

echo ("$row[1]"); so this should return the value 2 but it doesnt.

khaldryck

could you give us the actual query you're using, with the good names ?

if it's the last you gave, the problem comes from qty 2
you can't have spaces in field name.

jamesloi

When i echo ("$row[0]") it outputs both values 2,2. How can i get to put these values into an array so i can use $row[1], $row[2] etc..

khaldryck

if these are constant you want to get with $row[x]
then you have to change your query to select qty, '2', '2' from ...
that way $row[0] = the value of qty
$row[1]=2
$row[2]=2
but i don't see the point of doing this.

jamesloi

Ok here is the full code that i am using now

	$query2 = "SELECT qty FROM cart";

$result = mysql_query($query2);

            $row = mysql_fetch_array($result);

$query4 = "UPDATE CD_data SET  stock_level=stock_level-$row[1] WHERE Item_code='$row2[1]'";
mysql_query($query4);

echo ("$row[1]");

The values of in qty in the cart table are 3,2,2. When i echo ("$row[0]"); It returns 3. When i echo("$row[1]"); it reyurns nothing. Can anyone help...?

khaldryck

that's exactly what i said in first.

$query2 = "SELECT qty FROM cart"; // this query only return 1 item in a row.

$result = mysql_query($query2);

            $row = mysql_fetch_array($result); 

$query4 = "UPDATE CD_data SET  stock_level=stock_level-$row[1] WHERE Item_code='$row2[1]'";
mysql_query($query4);

echo ("$row[1]");

there is nothing in $row[1], only qty.

if you means there are 3 result returned by your query, then
you'll have to loop 3 times
that's the purpose of while($row=mysql_fetch_array($result)) { ...

it will fetch the first row of the result in $row[0] (3 if i understood well)
do your update with this value .
then it will fetch next row ... $row[0] will now have the value of the second row of the result (here 2)
will do the same as with the 3 value then fetch again.
again $row[0] will have value=2
then fetch again : no more values to fetch, so end of loop.

jamesloi

Thanks khaldryck,

i am a php beginner. Could you give me a code example of how to do what you suggested..?

khaldryck

that will be hard for me to give you an actual code usable by your script but here is something that should help you make your own.
i assume you get $code from somewhere else (dunno how)

$query="select qty from cart";
$result=mysql_query($query);
while($row=mysql_fetch_array($result)) {
$query2="UPDATE CD_data SET  stock_level=stock_level-$row[0] WHERE Item_code='".$code."'";
mysql_query($query2);
}

maybe you'll have to add some lines to change $code ...
also i think there should be a where condition in $query ...
but again as i don't know exactly what you're doing and what you want to do .. i can't help more.