(PHP 4 >= 4.2.0, PHP 5, PHP 7)
pg_connection_status — 获得连接状态
$connection
) : intpg_connection_status() 返回一个连接的状态。可能的状态为 PGSQL_CONNECTION_OK 和 PGSQL_CONNECTION_BAD。
Example #1 pg_connection_status() 例子
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
$stat = pg_connection_status($dbconn);
echo 'connection_status: '.$stat;
?>
Example #2 pg_connection_status() 例子
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
$stat = pg_connection_status($dbconn);
echo 'connection_status: '.$stat;
?>
The wiki page doesn't currently reflect that, but if you're passing PGSQL_CONNECT_ASYNC to pg_connect, creating the connection won't block and transitions through extra states expressed by those constants.
PGSQL_CONNECTION_AUTH_OK
PGSQL_CONNECTION_AWAITING_RESPONSE
PGSQL_CONNECTION_MADE
PGSQL_CONNECTION_SETENV
PGSQL_CONNECTION_SSL_STARTUP
PGSQL_CONNECTION_STARTED
Being careful with the comparison operators is not enough:
<?php
if (pg_connection_status($link)===PGSQL_CONNECTION_BAD)
reconnect($link);
?>
The reconnect won't be trigged when $link is null.
The manual is just wrong, there are three return values: PGSQL_CONNECTION_OK, PGSQL_CONNECTION_BAD, null
I think zytox is incorrect, at least in PHP 5.0.4.
It returns null, but you have to be careful with your comparison operators.
As an example:
<?php
unset($null);
if (pg_connection_status($null)===PGSQL_CONNECTION_OK)
echo 'this is not called';
if (pg_connection_status($null)==PGSQL_CONNECTION_OK)
echo 'this is called because NULL==0 is true';
?>
If the connection variable is NULL this function returns 0 in PHP 5.0.2. Havent figured out any more erratic values for the connection variable but be careful.