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
)
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}'");
?>