# pg_parameter_status

(PHP 5, PHP 7)

pg_parameter_status — Looks up a current parameter setting of the server

### 说明

pg_parameter_status ([ resource `$connection` ], string `$param_name` ) : string

Looks up a current parameter setting of the server.

Certain parameter values are reported by the server automatically at connection startup or whenever their values change. pg_parameter_status() can be used to interrogate these settings. It returns the current value of a parameter if known, or `FALSE` if the parameter is not known.

Parameters reported as of PostgreSQL 8.0 include server_version, server_encoding, client_encoding, is_superuser, session_authorization, DateStyle, TimeZone, and integer_datetimes. (server_encoding, TimeZone, and integer_datetimes were not reported by releases before 8.0.) Note that server_version, server_encoding and integer_datetimes cannot change after PostgreSQL startup.

PostgreSQL 7.3 or lower servers do not report parameter settings, pg_parameter_status() includes logic to obtain values for server_version and client_encoding anyway. Applications are encouraged to use pg_parameter_status() rather than ad hoc code to determine these values.

Caution

On a pre-7.4 PostgreSQL server, changing client_encoding via SET after connection startup will not be reflected by pg_parameter_status().

### 参数

`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().

`param_name`

  Possible `param_name` values include server_version, server_encoding, client_encoding, is_superuser, session_authorization, DateStyle, TimeZone, and integer_datetimes.

### 返回值

A string containing the value of the parameter, `FALSE` on failure or invalid `param_name`.

### 范例

Example #1 pg_parameter_status() example

    <?php
      $dbconn = pg_connect("dbname=publisher") or die("Could not connect");

      echo "Server encoding: ", pg_parameter_status($dbconn, "server_encoding");
    ?>

以上例程会输出：

    Server encoding: SQL_ASCII