postgreSQL+PHP: array question

[christina125]

I am using PHP to access a PostgreSQL database for an online banking application. I am having some problems with arrays.

//assume database connectivity
$sql = "some SQL statement"
$result = pg_query ($dbconn, $sql);
$data = pg_fetch_row ($result);
$ans = Array ();

//in this while loop I want to put the rows that satisfied a condition into the array $ans

while ($data != false) {
if cond {
$ans[] = $data;
$data = pg_fetch_row ($result);
}
}

I am really not familiar with the array syntax and could not find any relevant examples. Can someone tell me how to store an array $data into another array $ans and later to retrieve the values? Further, is there a way to create the array $ans = Array () with a give array size like $size?

Thank you so much!!!

[[deleted]]

Looks like you are unfamiliar with more than just arrays 🙂

$data = pg_fetch_row ($result);

pg_fetch_row() requires a rownumber to indicate which of the resultset rows you want to fetch.

Furthermore, your method will fail if there are no results to fetch, you should check wether there are any results to fetch before you fetch them

Using pg_fetch_assoc() rather than pg_fetch_row(), will give you an associative array, which means you can use column names instead of fieldnumbers (much easier to work with)

//assume database connectivity
$sql = "some SQL statement"
if (!$result = pg_query ($dbconn, $sql))
{
echo 'query failed, print psql error here';
exit;
}
else
{
// Did the query return any results?
$iNumberOfResults = pg_num_rows($result);
$aRows[]=array();
if ($iNumberOfResults>0)
{
// yes there were results, fetch them
for ($iT = 0; $iT< $iNumberOfResults; $iT++)
{
$aRows[] = pg_fetch_assoc($result, $iT) ;
}
}

now you shoukd have an array $aRows:

echo 'Number of rows in array:'.count($aRows);

and you can access the data like this:

echo $aRows[$rownumber]['columnname'];

[Sxooter]

Actually, vincente, as of PHP 4.2.x, you can iterate over pg_fetch_array without an index, and it works like mysql's function, it auto-steps to the next set each time.

So, the loop can be something like:

while ($row = pg_fetch_array($res)){
  $names[] = $row['lastname'];
}

[[deleted]]

"as of PHP 4.2.x, you can iterate over pg_fetch_array without an index, "

schweeeeet!

[Sxooter]

Actually, I looked it up to be sure, and it's since 4.1.0, not 4.2.0 like I said originally.