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 )

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. The same parameter may appear more than once in the query; the same value will be used in that case. 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.

User-supplied values should always be passed as parameters, not interpolated into the query string, where they form possible SQL injection attack vectors and introduce bugs when handling data containing quotes. If for some reason you cannot use a parameter, ensure that interpolated values are properly escaped.

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.

Values intended for bytea fields are not supported as parameters. Use pg_escape_bytea instead, or use the large object functions.

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}'");

?>

See Also

  • pg_query