Question

我有两个php文件，其中一个是类。我试图包含具有连接到数据库的$conn变量的文件。问题是我收到了这个错误：

 Notice: Undefined variable: conn in /home/yuran/public_html/avec/DatabaseContent.php on line 20

 Fatal error: Call to a member function prepare() on a non-object in /home/yuran/public_html/avec/DatabaseContent.php on line 20

以下是代码：

connection.php

<?php
    require_once('constants.php');

    try{
    //Create a database connection
        $conn = new PDO("mysql:host=".DB_SERVER.";"."dbname=".DB_NAME,DB_USER, DB_PASS);
    } catch(PDOException $pe){
        die("Could not connect to the database ".DB_NAME.": ".$pe->getMessage());
    }

?>

DatabaseContent.php

<?php
include('inc/conn/connection.php');

class DatabaseContent{

public function fetchAllRows($table, $rowOrder, $direction){
        $this->sql .= "ORDER BY :roworder :direction";
        $q = $conn->prepare($this->sql);
        $q->execute(array(':table'=>$table, 'roworder'=>$rowOrder, ':direction'=>$direction));
        $q->setFetchMode(PDO::FETCH_ASSOC);

        return $q;
    }

Answer 1

在课堂外包含该文件将无效。

您可以将public function up() { Schema::create('image_post', function (Blueprint $table) { $table->engine = 'InnoDB'; $table->increments('id'); $table->integer('image_id')->unsigned()->index(); $table->integer('post_id')->unsigned()->index(); $table->timestamps(); }); Schema::table('image_post', function($table) { $table->foreign('image_id')->references('id')->on('image')->onDelete('cascade'); $table->foreign('post_id')->references('id')->on('post')->onDelete('cascade'); }); }变量作为参数传递，因为您也无法在函数中包含该文件。

所以改变你的

$con

到

public function fetchAllRows($table, $rowOrder, $direction)

当您调用该函数时，只需将连接链接作为函数调用中的参数传递。

包括连接文件到类＆＃34;未定义变量conn＆＃34;

1 个答案: