pg_put_line
When inserting into a pg column of type bool, you cannot supply a PHP type of bool. You must instead use a string "t" or "f". PHP attempts to change boolean values supplied as parameters to strings, and then attempts to use a blank string for false.
Example of Failure:
pg_query_params('insert into table1 (bool_column) values ($1)', array(false));
Works:
pg_query_params('insert into lookup_permissions (system) values ($1)', array(false ? 't' : 'f'));
pg_query_params
(PHP 5 >= 5.1.0)
pg_query_params — Submits a command to the server and waits for the result, with the ability to pass parameters separately from the SQL command text.
Description
resource pg_query_params
( resource $connection
, string $query
, array $params
)
resource pg_query_params
( string $query
, array $params
)
Submits a command to the server and waits for the result, with the ability to pass parameters separately from the SQL command text.
pg_query_params() is like pg_query(), but offers additional functionality: parameter values can be specified separately from the command string proper. pg_query_params() is supported only against PostgreSQL 7.4 or higher connections; it will fail when using earlier versions.
If parameters are used, they are referred to in the query string as $1, $2, etc. params specifies the actual values of the parameters. A NULL value in this array means the corresponding parameter is SQL NULL.
The primary advantage of pg_query_params() over pg_query() is that parameter values may be separated from the query string, thus avoiding the need for tedious and error-prone quoting and escaping. Unlike pg_query(), pg_query_params() allows at most one SQL command in the given string. (There can be semicolons in it, but not more than one nonempty command.)
Parameters
- connection
-
PostgreSQL database connection resource. When connection is not present, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().
- query
-
The parameterized SQL statement. Must contain only a single statement. (multiple statements separated by semi-colons are not allowed.) If any parameters are used, they are referred to as $1, $2, etc.
- params
-
An array of parameter values to substitute for the $1, $2, etc. placeholders in the original prepared query string. The number of elements in the array must match the number of placeholders.
Return Values
A query result resource on success, or FALSE on failure.
Examples
Example #1 Using pg_query_params()
<?php
// Connect to a database named "mary"
$dbconn = pg_connect("dbname=mary");
// Find all shops named Joe's Widgets. Note that it is not necessary to
// escape "Joe's Widgets"
$result = pg_query_params($dbconn, 'SELECT * FROM shops WHERE name = $1', array("Joe's Widgets"));
// Compare against just using pg_query
$str = pg_escape_string("Joe's Widgets");
$result = pg_query($dbconn, "SELECT * FROM shops WHERE name = '{$str}'");
?>
add a note
User Contributed Notespg_query_params
jsnell at e-normous dot com
26-Sep-2007 10:57
26-Sep-2007 10:57
dt309 at f2s dot com
22-Dec-2006 08:11
22-Dec-2006 08:11
If you need to provide multiple possible values for a field in a select query, then the following will help.
<?php
// Assume that $values[] is an array containing the values you are interested in.
$values = array(1, 4, 5, 8);
// To select a variable number of arguments using pg_query() you can use:
$valuelist = implode(', ', $values);
$query = "SELECT * FROM table1 WHERE col1 IN ($valuelist)";
$result = pg_query($query)
or die(pg_last_error());
// You may therefore assume that the following will work.
$query = 'SELECT * FROM table1 WHERE col1 IN ($1)';
$result = pg_query_params($query, array($valuelist))
or die(pg_last_error());
// Produces error message: 'ERROR: invalid input syntax for integer'
// It only works when a SINGLE value specified.
// Instead you must use the following approach:
$valuelist = '{' . implode(', ', $values . '}'
$query = 'SELECT * FROM table1 WHERE col1 = ANY ($1)';
$result = pg_query_params($query, array($valuelist));
?>
The error produced in this example is generated by PostGreSQL.
The last method works by creating a SQL array containing the desired values. 'IN (...)' and ' = ANY (...)' are equivalent, but ANY is for working with arrays, and IN is for working with simple lists.
mledford
04-Oct-2006 03:18
04-Oct-2006 03:18
If you are trying to replicate the function pg_query_params, you might also want to support NULL values. While is_int returns true for a NULL value, the formatting for the SQL.
function pg_query_params( $db, $query, $parameters ) {
// Escape parameters as required & build parameters for callback function
global $pg_query_params__parameters;
foreach( $parameters as $k=>$v ) {
if ( is_null($v) ) {
$parameters[$k] = 'NULL';
} else {
$parameters[$k] = ( is_int( $v ) ? $v : "'".pg_escape_string( $v )."'" );
}
}
$pg_query_params__parameters = $parameters;
// Call using pg_query
return pg_query( $db, preg_replace_callback( '/\$([0-9]+)/', 'pg_query_params__callback', $query));
}
cc+php at c2se dot com
02-Sep-2006 12:17
02-Sep-2006 12:17
This is a useful function for preventing SQL injection attacks, so, for those of us who are not yet able to upgrade to PHP5.1, here is a replacement function which works similarly on older versions of PHP...
<?php # Parameterised query implementation for Postgresql and older versions of PHP
if( !function_exists( 'pg_query_params' ) ) {
function pg_query_params__callback( $at ) {
global $pg_query_params__parameters;
return $pg_query_params__parameters[ $at[1]-1 ];
}
function pg_query_params( $db, $query, $parameters ) {
// Escape parameters as required & build parameters for callback function
global $pg_query_params__parameters;
foreach( $parameters as $k=>$v )
$parameters[$k] = ( is_int( $v ) ? $v : "'".pg_escape_string( $v )."'" );
$pg_query_params__parameters = $parameters;
// Call using pg_query
return pg_query( $db, preg_replace_callback( '/\$([0-9]+)/', 'pg_query_params__callback', $query ) );
}
}
// Example: pg_query_params( $db_resource, "SELECT * FROM table WHERE col1=$1 AND col2=$2", array( 42, "It's ok" ) );
?>