Php 如何仅使用一次oci_connect（），然后包含其文件

我正在使用PHP和oracle数据库制作一个网站。 我有一个connect.php文件

<?php 
$connect_error = "We are Experiencing Some Technical Difficulty";
oci_connect("asim","asim","localhost/xe") or die($connect_error);
?>

我必须包括行

$conn=oci_connect（“asim”、“asim”、“localhost/xe”）在每个函数中

有没有办法避免这种情况。

oci\u执行
而oci_parse需要两个参数，其中一个是您需要将第一次调用
oci_connect（）
的结果设置为如下变量：

<?php 
$connect_error = "We are Experiencing Some Technical Difficulty";
$conn = oci_connect("asim","asim","localhost/xe") or die($connect_error);
?>

<?php 
$connect_error = "We are Experiencing Some Technical Difficulty";
$conn = oci_connect("asim","asim","localhost/xe") or die($connect_error);
?>

function user_exists($username){
    global $conn;

    $username = sanitize($username); 
    $stmt = oci_parse($conn,"SELECT COUNT(username)....");
    oci_execute($stmt); 
    return ($stmt > 0) ? true:false; 
}