<?php 
$host="host=127.0.0.1";//网络层
$port="port=5432";//传输层
$dbname="dbname=postgres";//会话层
$credentials="user=postgres password=root";//表示层
//应用层 来连接
$db=pg_connect("$host $post $dbname $credentials");
if(!$db){
    echo "连接失败\n";
}else{
    echo "连接成功\n";
}