> Return Values
>
> Returns TRUE on success or FALSE on failure. Returns string if
> PGSQL_DML_STRING is passed via options.
I have found in my copy of PHP (version 4.4.0) that if you use the 'PGSQL_DML_STRING' option, the function does not execute any query. It merely returns the query which would have been executed.
Another thing I noticed, pg_update does not seem to make use of pg_trace (atleast in 4.4.0).
PS this isn't a bug report, just an explanation of some undocumented features I noticed. As the manual says, the function is still in development so this behaviour may differ from version to version.
pg_update
(PHP 4 >= 4.3.0, PHP 5)
pg_update — Update table
Description
$connection
, string $table_name
, array $data
, array $condition
[, int $options = PGSQL_DML_EXEC
] )pg_update() updates records that matches condition with data. If options is specified, pg_convert() is applied to data with specified options.
This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.
Parameters
-
connection -
PostgreSQL database connection resource.
-
table_name -
Name of the table into which to update rows.
-
data -
An array whose keys are field names in the table
table_name, and whose values are what matched rows are to be updated to. -
condition -
An array whose keys are field names in the table
table_name, and whose values are the conditions that a row must meet to be updated. -
options -
Any number of
PGSQL_CONV_OPTS,PGSQL_DML_NO_CONV,PGSQL_DML_EXECorPGSQL_DML_STRINGcombined. IfPGSQL_DML_STRINGis part of theoptionsthen query string is returned.
Return Values
Returns TRUE on success or FALSE on failure. Returns string if PGSQL_DML_STRING is passed
via options.
Examples
Example #1 pg_update() example
<?php
$db = pg_connect('dbname=foo');
$data = array('field1'=>'AA', 'field2'=>'BB');
// This is safe, since $_POST is converted automatically
$res = pg_update($db, 'post_log', $_POST, $data);
if ($res) {
echo "Data is updated: $res\n";
} else {
echo "User must have sent wrong inputs\n";
}
?>
Using pg_update() and pg_insert() without key validation is not secure!
You need to check which data pairs you get, and if you want to allow to updated this column.
Example:
You have a table with tree colums: username, password, userlevel.
Your users may change only their username, and their password but not their userlevel.
If you don't filter the keys in the request array, every user can now change his userlevel just by sending a POST Request with "userlevel=>100".
So if you don't check if the key are allowed in your request array you'll get serious sql injection vulnarabilities in your code.
This function is similar to PEAR::DB's autoExecute() function, with the only difference being that the where clause is an array instead of a string.
Also, if you want to use your instance of the DB class with this function, you can reference the existing resource connection with $db->connection.
An example would be:
<?
pg_update($db->connection, $arr_update, $arr_where);
?>
